<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2024 Workiva-->
<!--r:66b623ab-9225-402b-a0c6-24e3a7691b89,g:e3f9fc8c-a66e-460e-a5ac-dbd40638ae3d-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://www.htgc.com/role/Cover" xlink:type="simple" xlink:href="htgc-20240630.xsd#Cover"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/Cover" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationTable_ddcbe0e7-2ce0-47f0-9319-430f5d7575f5" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentInformationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_DocumentInformationTable_ddcbe0e7-2ce0-47f0-9319-430f5d7575f5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_1e493577-3dcc-4b05-8b2f-b725107564e6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_DocumentInformationTable_ddcbe0e7-2ce0-47f0-9319-430f5d7575f5" xlink:to="loc_us-gaap_StatementClassOfStockAxis_1e493577-3dcc-4b05-8b2f-b725107564e6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_1e493577-3dcc-4b05-8b2f-b725107564e6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_1e493577-3dcc-4b05-8b2f-b725107564e6" xlink:to="loc_us-gaap_ClassOfStockDomain_1e493577-3dcc-4b05-8b2f-b725107564e6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_b10fb6aa-e06e-45c7-937d-85f2925133fc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_1e493577-3dcc-4b05-8b2f-b725107564e6" xlink:to="loc_us-gaap_ClassOfStockDomain_b10fb6aa-e06e-45c7-937d-85f2925133fc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CommonStockParValueZeroPointZeroZeroOnePerShareMember_1926508e-6be1-4de6-9a45-04bfae242694" xlink:href="htgc-20240630.xsd#htgc_CommonStockParValueZeroPointZeroZeroOnePerShareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_b10fb6aa-e06e-45c7-937d-85f2925133fc" xlink:to="loc_htgc_CommonStockParValueZeroPointZeroZeroOnePerShareMember_1926508e-6be1-4de6-9a45-04bfae242694" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SixPointTwoFiveNotesDueTwoThousandThirtyThreeMember_04529c9b-75f2-461d-a5aa-441c6bae6497" xlink:href="htgc-20240630.xsd#htgc_SixPointTwoFiveNotesDueTwoThousandThirtyThreeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_b10fb6aa-e06e-45c7-937d-85f2925133fc" xlink:to="loc_htgc_SixPointTwoFiveNotesDueTwoThousandThirtyThreeMember_04529c9b-75f2-461d-a5aa-441c6bae6497" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_3dcdd7fa-e193-4e38-8547-ffceade88ede" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentType"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_DocumentType_3dcdd7fa-e193-4e38-8547-ffceade88ede" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentQuarterlyReport_9e0b29ee-56d7-4079-b067-3dacb99a13d3" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentQuarterlyReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_DocumentQuarterlyReport_9e0b29ee-56d7-4079-b067-3dacb99a13d3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_7b7139fb-2db4-48d9-9a22-cab11a854fe2" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentPeriodEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_DocumentPeriodEndDate_7b7139fb-2db4-48d9-9a22-cab11a854fe2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentTransitionReport_fbb8b373-66d5-45ff-aa81-0a9fc7bb35f3" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentTransitionReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_DocumentTransitionReport_fbb8b373-66d5-45ff-aa81-0a9fc7bb35f3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_fcb5a9f0-470b-4b2a-91c7-840829f92403" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityFileNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_EntityFileNumber_fcb5a9f0-470b-4b2a-91c7-840829f92403" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_68818d80-7ff9-409e-9903-c1c8b8d9cf59" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityRegistrantName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_EntityRegistrantName_68818d80-7ff9-409e-9903-c1c8b8d9cf59" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_2aa500da-5d29-4513-886b-11087447763b" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_EntityIncorporationStateCountryCode_2aa500da-5d29-4513-886b-11087447763b" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_aee46e57-8fc7-4e45-8e90-ee55b51a321f" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_EntityTaxIdentificationNumber_aee46e57-8fc7-4e45-8e90-ee55b51a321f" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_8c4d38f1-951c-4409-b3cb-77d9e37e9f1a" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressAddressLine1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_EntityAddressAddressLine1_8c4d38f1-951c-4409-b3cb-77d9e37e9f1a" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine2_9aec9c26-5386-4d90-80a4-08daa1f9d66a" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressAddressLine2"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_EntityAddressAddressLine2_9aec9c26-5386-4d90-80a4-08daa1f9d66a" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_10e508c2-6d16-4506-96c9-c765885dcdfd" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressCityOrTown"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_EntityAddressCityOrTown_10e508c2-6d16-4506-96c9-c765885dcdfd" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_10dde241-c06d-4229-8f96-7c0507e3f33e" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressStateOrProvince"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_EntityAddressStateOrProvince_10dde241-c06d-4229-8f96-7c0507e3f33e" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_e94477c8-6f69-44f4-9279-6e64fa809b5d" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressPostalZipCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_EntityAddressPostalZipCode_e94477c8-6f69-44f4-9279-6e64fa809b5d" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_48faf1a3-d172-4868-a813-7915f569b141" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_CityAreaCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_CityAreaCode_48faf1a3-d172-4868-a813-7915f569b141" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_d9a99529-bccf-4689-b3f3-353b76d25560" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_LocalPhoneNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_LocalPhoneNumber_d9a99529-bccf-4689-b3f3-353b76d25560" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_d52e6371-b211-4788-ab34-839df2a23b86" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_Security12bTitle"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_Security12bTitle_d52e6371-b211-4788-ab34-839df2a23b86" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_3686aec4-7c7e-48ee-9f93-057335963885" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_TradingSymbol"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_TradingSymbol_3686aec4-7c7e-48ee-9f93-057335963885" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_860426b3-9e97-44e9-b696-9b3f9f9dc8f9" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_SecurityExchangeName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_SecurityExchangeName_860426b3-9e97-44e9-b696-9b3f9f9dc8f9" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCurrentReportingStatus_2de21477-5763-453b-ad15-edf95c5866b7" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityCurrentReportingStatus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_EntityCurrentReportingStatus_2de21477-5763-453b-ad15-edf95c5866b7" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInteractiveDataCurrent_fa4eac0e-c14a-4e3f-9860-529258dc1b6a" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityInteractiveDataCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_EntityInteractiveDataCurrent_fa4eac0e-c14a-4e3f-9860-529258dc1b6a" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFilerCategory_b23f4123-a700-4c4f-9ccf-24834b3bef68" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityFilerCategory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_EntityFilerCategory_b23f4123-a700-4c4f-9ccf-24834b3bef68" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitySmallBusiness_5cf53e0f-94d1-40a8-a936-8c01699720c4" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntitySmallBusiness"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_EntitySmallBusiness_5cf53e0f-94d1-40a8-a936-8c01699720c4" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_f0da6a01-300f-4bd4-b0a0-05b23396ce77" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_EntityEmergingGrowthCompany_f0da6a01-300f-4bd4-b0a0-05b23396ce77" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityShellCompany_df66c0bd-fc01-4add-84dc-1537cbfa2931" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityShellCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_EntityShellCompany_df66c0bd-fc01-4add-84dc-1537cbfa2931" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCommonStockSharesOutstanding_bfa97bd6-0e4e-4d3e-a93f-0cfad8161fd9" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityCommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_EntityCommonStockSharesOutstanding_bfa97bd6-0e4e-4d3e-a93f-0cfad8161fd9" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_3d0e52ba-7ff0-4d73-87b2-5d41a8e1f53b" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityCentralIndexKey"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_EntityCentralIndexKey_3d0e52ba-7ff0-4d73-87b2-5d41a8e1f53b" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalYearFocus_e6b9cee2-4457-471a-8efc-ac4a31d1f2a6" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentFiscalYearFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_DocumentFiscalYearFocus_e6b9cee2-4457-471a-8efc-ac4a31d1f2a6" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalPeriodFocus_7dffdd67-2e50-4b2c-9412-d5ab06e57c6f" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentFiscalPeriodFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_DocumentFiscalPeriodFocus_7dffdd67-2e50-4b2c-9412-d5ab06e57c6f" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CurrentFiscalYearEndDate_fbf668f0-339c-420c-92dc-60c762e94463" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_CurrentFiscalYearEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_CurrentFiscalYearEndDate_fbf668f0-339c-420c-92dc-60c762e94463" xlink:type="arc" order="28"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_5fd213e5-d40a-4c62-a9ac-99c87cf7661f" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_AmendmentFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_38f4a08a-ab8f-4bcd-b320-b0d6e1553670" xlink:to="loc_dei_AmendmentFlag_5fd213e5-d40a-4c62-a9ac-99c87cf7661f" xlink:type="arc" order="29"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/CONSOLIDATEDSTATEMENTSOFASSETSANDLIABILITIES" xlink:type="simple" xlink:href="htgc-20240630.xsd#CONSOLIDATEDSTATEMENTSOFASSETSANDLIABILITIES"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/CONSOLIDATEDSTATEMENTSOFASSETSANDLIABILITIES" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_6907f7a1-9b0a-47f0-a571-6e7c4921c6cc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_88a0015c-89e4-45c2-8135-9ab205d07eca" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_6907f7a1-9b0a-47f0-a571-6e7c4921c6cc" xlink:to="loc_us-gaap_StatementTable_88a0015c-89e4-45c2-8135-9ab205d07eca" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationAxis_704a07bc-827d-4059-aecc-e34b5da29cae" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentIssuerAffiliationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_88a0015c-89e4-45c2-8135-9ab205d07eca" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationAxis_704a07bc-827d-4059-aecc-e34b5da29cae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_704a07bc-827d-4059-aecc-e34b5da29cae_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_704a07bc-827d-4059-aecc-e34b5da29cae" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_704a07bc-827d-4059-aecc-e34b5da29cae_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_e87982b9-ce15-429a-b4a5-fc5f56a54fb3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_704a07bc-827d-4059-aecc-e34b5da29cae" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_e87982b9-ce15-429a-b4a5-fc5f56a54fb3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentUnaffiliatedIssuerMember_d5eb3528-f750-4c3d-af62-a0cb1a8a253e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentUnaffiliatedIssuerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationDomain_e87982b9-ce15-429a-b4a5-fc5f56a54fb3" xlink:to="loc_us-gaap_InvestmentUnaffiliatedIssuerMember_d5eb3528-f750-4c3d-af62-a0cb1a8a253e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentAffiliatedIssuerControlledMember_9acfeddf-8e17-42ce-9b93-6d46c47a0c84" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentAffiliatedIssuerControlledMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationDomain_e87982b9-ce15-429a-b4a5-fc5f56a54fb3" xlink:to="loc_us-gaap_InvestmentAffiliatedIssuerControlledMember_9acfeddf-8e17-42ce-9b93-6d46c47a0c84" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract_63ca4b00-2440-4d8b-a1e4-4bd36566893a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6907f7a1-9b0a-47f0-a571-6e7c4921c6cc" xlink:to="loc_us-gaap_AssetsAbstract_63ca4b00-2440-4d8b-a1e4-4bd36566893a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtFairValue_4248c2cb-b613-48ab-b9a9-22a0ee8c44d0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_63ca4b00-2440-4d8b-a1e4-4bd36566893a" xlink:to="loc_us-gaap_InvestmentOwnedAtFairValue_4248c2cb-b613-48ab-b9a9-22a0ee8c44d0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_c782a667-5fe7-4281-baec-0d4ca7b9c0f6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_63ca4b00-2440-4d8b-a1e4-4bd36566893a" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_c782a667-5fe7-4281-baec-0d4ca7b9c0f6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCash_f4f5ff8f-ffa5-4969-bce2-de1a4e5bda29" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestrictedCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_63ca4b00-2440-4d8b-a1e4-4bd36566893a" xlink:to="loc_us-gaap_RestrictedCash_f4f5ff8f-ffa5-4969-bce2-de1a4e5bda29" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestReceivable_c3ba579a-07d9-420b-91ad-1805ae919c30" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_63ca4b00-2440-4d8b-a1e4-4bd36566893a" xlink:to="loc_us-gaap_InterestReceivable_c3ba579a-07d9-420b-91ad-1805ae919c30" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_5873f0ee-dbb9-4e91-85b5-57e953e5019e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_63ca4b00-2440-4d8b-a1e4-4bd36566893a" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_5873f0ee-dbb9-4e91-85b5-57e953e5019e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssets_930e5db0-45e5-45ef-8298-2ca86537e32d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_63ca4b00-2440-4d8b-a1e4-4bd36566893a" xlink:to="loc_us-gaap_OtherAssets_930e5db0-45e5-45ef-8298-2ca86537e32d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_e4698b11-1a3c-4d1e-9804-20afc93ef24f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_63ca4b00-2440-4d8b-a1e4-4bd36566893a" xlink:to="loc_us-gaap_Assets_e4698b11-1a3c-4d1e-9804-20afc93ef24f" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAbstract_96915da1-c50f-4b63-8bd1-040f0533ab9f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LiabilitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6907f7a1-9b0a-47f0-a571-6e7c4921c6cc" xlink:to="loc_us-gaap_LiabilitiesAbstract_96915da1-c50f-4b63-8bd1-040f0533ab9f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLongTermDebt_557b9256-b3f0-4c7e-95a2-7481e1c8b5f7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherLongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_96915da1-c50f-4b63-8bd1-040f0533ab9f" xlink:to="loc_us-gaap_OtherLongTermDebt_557b9256-b3f0-4c7e-95a2-7481e1c8b5f7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent_9d20e185-f250-4e95-a63f-54234b35cfd2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_96915da1-c50f-4b63-8bd1-040f0533ab9f" xlink:to="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAndNoncurrent_9d20e185-f250-4e95-a63f-54234b35cfd2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiability_7f5138d9-73f2-4374-a2d1-268b203de514" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingLeaseLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_96915da1-c50f-4b63-8bd1-040f0533ab9f" xlink:to="loc_us-gaap_OperatingLeaseLiability_7f5138d9-73f2-4374-a2d1-268b203de514" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Liabilities_a0552563-20b6-40f2-bf8e-6a58544df1ae" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Liabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract_96915da1-c50f-4b63-8bd1-040f0533ab9f" xlink:to="loc_us-gaap_Liabilities_a0552563-20b6-40f2-bf8e-6a58544df1ae" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityAbstract_e1ced60d-664c-4f60-a932-541865ad5034" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6907f7a1-9b0a-47f0-a571-6e7c4921c6cc" xlink:to="loc_us-gaap_StockholdersEquityAbstract_e1ced60d-664c-4f60-a932-541865ad5034" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockValue_8071d7cf-df1c-480d-96dc-727b256184af" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_e1ced60d-664c-4f60-a932-541865ad5034" xlink:to="loc_us-gaap_CommonStockValue_8071d7cf-df1c-480d-96dc-727b256184af" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapital_dad37419-957e-48bb-8914-b7db20e92157" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AdditionalPaidInCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_e1ced60d-664c-4f60-a932-541865ad5034" xlink:to="loc_us-gaap_AdditionalPaidInCapital_dad37419-957e-48bb-8914-b7db20e92157" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_3a5d2842-e5e1-49dd-9ed3-3c6ff55f51b2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetainedEarningsAccumulatedDeficit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_e1ced60d-664c-4f60-a932-541865ad5034" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_3a5d2842-e5e1-49dd-9ed3-3c6ff55f51b2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_301515e4-5c1d-4d35-ba95-990424d41b90" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityAbstract_e1ced60d-664c-4f60-a932-541865ad5034" xlink:to="loc_us-gaap_StockholdersEquity_301515e4-5c1d-4d35-ba95-990424d41b90" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_28b08870-3d34-4f8c-bbc5-958a83ae16bf" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LiabilitiesAndStockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6907f7a1-9b0a-47f0-a571-6e7c4921c6cc" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_28b08870-3d34-4f8c-bbc5-958a83ae16bf" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_89fc81ed-33a7-4c51-89ef-4f2ac4b866b3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6907f7a1-9b0a-47f0-a571-6e7c4921c6cc" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_89fc81ed-33a7-4c51-89ef-4f2ac4b866b3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetAssetValuePerShare_46b0e51f-c042-4d02-a381-f0a4ada97be9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetAssetValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_6907f7a1-9b0a-47f0-a571-6e7c4921c6cc" xlink:to="loc_us-gaap_NetAssetValuePerShare_46b0e51f-c042-4d02-a381-f0a4ada97be9" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/CONSOLIDATEDSTATEMENTSOFASSETSANDLIABILITIESParenthetical" xlink:type="simple" xlink:href="htgc-20240630.xsd#CONSOLIDATEDSTATEMENTSOFASSETSANDLIABILITIESParenthetical"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/CONSOLIDATEDSTATEMENTSOFASSETSANDLIABILITIESParenthetical" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_07ebffab-15f8-497b-b480-83f4cf6aff86" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_268b4afd-e2b0-49bc-b881-b0b25a3637c7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_07ebffab-15f8-497b-b480-83f4cf6aff86" xlink:to="loc_us-gaap_StatementTable_268b4afd-e2b0-49bc-b881-b0b25a3637c7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_c8404d6a-51c5-4044-bd1a-6873a973c93a" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_268b4afd-e2b0-49bc-b881-b0b25a3637c7" xlink:to="loc_srt_ConsolidatedEntitiesAxis_c8404d6a-51c5-4044-bd1a-6873a973c93a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_c8404d6a-51c5-4044-bd1a-6873a973c93a_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_c8404d6a-51c5-4044-bd1a-6873a973c93a" xlink:to="loc_srt_ConsolidatedEntitiesDomain_c8404d6a-51c5-4044-bd1a-6873a973c93a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_24ed2005-d040-4d42-bf59-4f1a86f89a03" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_c8404d6a-51c5-4044-bd1a-6873a973c93a" xlink:to="loc_srt_ConsolidatedEntitiesDomain_24ed2005-d040-4d42-bf59-4f1a86f89a03" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_64be244b-e514-4b2c-b654-2416182f3d75" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_VariableInterestEntityPrimaryBeneficiaryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_24ed2005-d040-4d42-bf59-4f1a86f89a03" xlink:to="loc_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_64be244b-e514-4b2c-b654-2416182f3d75" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationAxis_dd59edec-8c8e-4604-908e-a35044d0e8f1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentIssuerAffiliationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_268b4afd-e2b0-49bc-b881-b0b25a3637c7" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationAxis_dd59edec-8c8e-4604-908e-a35044d0e8f1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_dd59edec-8c8e-4604-908e-a35044d0e8f1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_dd59edec-8c8e-4604-908e-a35044d0e8f1" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_dd59edec-8c8e-4604-908e-a35044d0e8f1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_1d81053c-d260-44fd-8ea1-0576178407da" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_dd59edec-8c8e-4604-908e-a35044d0e8f1" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_1d81053c-d260-44fd-8ea1-0576178407da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentUnaffiliatedIssuerMember_84955660-17db-4ceb-84c8-b97a1d277ae9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentUnaffiliatedIssuerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationDomain_1d81053c-d260-44fd-8ea1-0576178407da" xlink:to="loc_us-gaap_InvestmentUnaffiliatedIssuerMember_84955660-17db-4ceb-84c8-b97a1d277ae9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentAffiliatedIssuerControlledMember_8fe2fc96-dcfb-40fc-9d92-e1d530f94a82" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentAffiliatedIssuerControlledMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationDomain_1d81053c-d260-44fd-8ea1-0576178407da" xlink:to="loc_us-gaap_InvestmentAffiliatedIssuerControlledMember_8fe2fc96-dcfb-40fc-9d92-e1d530f94a82" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtCost_3466ee41-caec-4d41-bab0-7e423750b0b4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedAtCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_07ebffab-15f8-497b-b480-83f4cf6aff86" xlink:to="loc_us-gaap_InvestmentOwnedAtCost_3466ee41-caec-4d41-bab0-7e423750b0b4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCash_216ad9fe-e070-4b18-9cd8-73972880b0a5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestrictedCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_07ebffab-15f8-497b-b480-83f4cf6aff86" xlink:to="loc_us-gaap_RestrictedCash_216ad9fe-e070-4b18-9cd8-73972880b0a5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLongTermDebt_c7fb5ec7-2fe2-4a18-9269-9c85936fb605" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherLongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_07ebffab-15f8-497b-b480-83f4cf6aff86" xlink:to="loc_us-gaap_OtherLongTermDebt_c7fb5ec7-2fe2-4a18-9269-9c85936fb605" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_e84665b4-17c7-422f-a7db-cf744a8445da" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockParOrStatedValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_07ebffab-15f8-497b-b480-83f4cf6aff86" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_e84665b4-17c7-422f-a7db-cf744a8445da" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_aa207ebf-9263-4b2f-a6d1-63c00de5b872" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_07ebffab-15f8-497b-b480-83f4cf6aff86" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_aa207ebf-9263-4b2f-a6d1-63c00de5b872" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/CONSOLIDATEDSTATEMENTSOFOPERATIONSunaudited" xlink:type="simple" xlink:href="htgc-20240630.xsd#CONSOLIDATEDSTATEMENTSOFOPERATIONSunaudited"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/CONSOLIDATEDSTATEMENTSOFOPERATIONSunaudited" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_d61180cd-14b0-4cf8-9be7-baad305fd79a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_0f6b5091-4a3b-4c58-8ef1-744bed724a12" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_d61180cd-14b0-4cf8-9be7-baad305fd79a" xlink:to="loc_us-gaap_StatementTable_0f6b5091-4a3b-4c58-8ef1-744bed724a12" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationAxis_dc1f8e66-aa75-480a-ae2a-e77450c2db27" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentIssuerAffiliationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_0f6b5091-4a3b-4c58-8ef1-744bed724a12" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationAxis_dc1f8e66-aa75-480a-ae2a-e77450c2db27" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_dc1f8e66-aa75-480a-ae2a-e77450c2db27_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_dc1f8e66-aa75-480a-ae2a-e77450c2db27" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_dc1f8e66-aa75-480a-ae2a-e77450c2db27_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_20f16dca-3b18-4051-a95d-c586f0cddb12" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_dc1f8e66-aa75-480a-ae2a-e77450c2db27" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_20f16dca-3b18-4051-a95d-c586f0cddb12" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentUnaffiliatedIssuerMember_691699e2-bb97-47af-b66a-b751bc60c2db" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentUnaffiliatedIssuerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationDomain_20f16dca-3b18-4051-a95d-c586f0cddb12" xlink:to="loc_us-gaap_InvestmentUnaffiliatedIssuerMember_691699e2-bb97-47af-b66a-b751bc60c2db" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentAffiliatedIssuerControlledMember_7bf9d412-efdb-4bc5-9431-9fc02e4e65a0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentAffiliatedIssuerControlledMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationDomain_20f16dca-3b18-4051-a95d-c586f0cddb12" xlink:to="loc_us-gaap_InvestmentAffiliatedIssuerControlledMember_7bf9d412-efdb-4bc5-9431-9fc02e4e65a0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetInvestmentIncomeAbstract_9e07a578-fe09-499a-ba0a-955eadbb3506" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetInvestmentIncomeAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_d61180cd-14b0-4cf8-9be7-baad305fd79a" xlink:to="loc_us-gaap_NetInvestmentIncomeAbstract_9e07a578-fe09-499a-ba0a-955eadbb3506" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndDividendIncomeOperating_31b431b0-918d-4393-ba93-a5679a4fb58f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestAndDividendIncomeOperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetInvestmentIncomeAbstract_9e07a578-fe09-499a-ba0a-955eadbb3506" xlink:to="loc_us-gaap_InterestAndDividendIncomeOperating_31b431b0-918d-4393-ba93-a5679a4fb58f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FeeIncome_6767b7af-3283-47ea-87d2-99cc62012cd2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FeeIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetInvestmentIncomeAbstract_9e07a578-fe09-499a-ba0a-955eadbb3506" xlink:to="loc_us-gaap_FeeIncome_6767b7af-3283-47ea-87d2-99cc62012cd2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossInvestmentIncomeOperating_e61804e5-9a5a-49f6-b3f1-b426324cf38a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GrossInvestmentIncomeOperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetInvestmentIncomeAbstract_9e07a578-fe09-499a-ba0a-955eadbb3506" xlink:to="loc_us-gaap_GrossInvestmentIncomeOperating_e61804e5-9a5a-49f6-b3f1-b426324cf38a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpensesAbstract_3ac8da4e-e926-48d9-accb-6daee938a514" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingExpensesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_d61180cd-14b0-4cf8-9be7-baad305fd79a" xlink:to="loc_us-gaap_OperatingExpensesAbstract_3ac8da4e-e926-48d9-accb-6daee938a514" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseDebt_a229ff4b-2b57-4ec9-a65f-ccf19465b816" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestExpenseDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_3ac8da4e-e926-48d9-accb-6daee938a514" xlink:to="loc_us-gaap_InterestExpenseDebt_a229ff4b-2b57-4ec9-a65f-ccf19465b816" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtRelatedCommitmentFeesAndDebtIssuanceCosts_692639dd-f264-483c-9b64-7b9d3509f0ea" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtRelatedCommitmentFeesAndDebtIssuanceCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_3ac8da4e-e926-48d9-accb-6daee938a514" xlink:to="loc_us-gaap_DebtRelatedCommitmentFeesAndDebtIssuanceCosts_692639dd-f264-483c-9b64-7b9d3509f0ea" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_b447b0c2-ad2b-4018-a69a-2f536425b636" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_3ac8da4e-e926-48d9-accb-6daee938a514" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_b447b0c2-ad2b-4018-a69a-2f536425b636" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeOperatingTaxExpenseBenefit_6a320e8d-580e-467a-b164-73bb430c7ef9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentIncomeOperatingTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_3ac8da4e-e926-48d9-accb-6daee938a514" xlink:to="loc_us-gaap_InvestmentIncomeOperatingTaxExpenseBenefit_6a320e8d-580e-467a-b164-73bb430c7ef9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementCompensationItemsAbstract_91d32c89-2679-426e-bc12-2f2c9d2021d2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementCompensationItemsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_3ac8da4e-e926-48d9-accb-6daee938a514" xlink:to="loc_us-gaap_IncomeStatementCompensationItemsAbstract_91d32c89-2679-426e-bc12-2f2c9d2021d2" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LaborAndRelatedExpense_1cba1c64-d32e-4989-8bfc-22f20bca6c93" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LaborAndRelatedExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementCompensationItemsAbstract_91d32c89-2679-426e-bc12-2f2c9d2021d2" xlink:to="loc_us-gaap_LaborAndRelatedExpense_1cba1c64-d32e-4989-8bfc-22f20bca6c93" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeBenefitsAndShareBasedCompensation_09178612-7deb-4d98-825d-184fb70f9d55" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeBenefitsAndShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementCompensationItemsAbstract_91d32c89-2679-426e-bc12-2f2c9d2021d2" xlink:to="loc_us-gaap_EmployeeBenefitsAndShareBasedCompensation_09178612-7deb-4d98-825d-184fb70f9d55" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_EmployeeCompensation_21184d16-e016-4633-8332-c0816f7bfb40" xlink:href="htgc-20240630.xsd#htgc_EmployeeCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementCompensationItemsAbstract_91d32c89-2679-426e-bc12-2f2c9d2021d2" xlink:to="loc_htgc_EmployeeCompensation_21184d16-e016-4633-8332-c0816f7bfb40" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_00c73b78-ed2d-49fc-80e3-04c30c097b90" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_3ac8da4e-e926-48d9-accb-6daee938a514" xlink:to="loc_us-gaap_OperatingExpenses_00c73b78-ed2d-49fc-80e3-04c30c097b90" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ExpensesAllocatedToAdviserSubsidiary1_553a6ecc-64f5-434d-9649-462dc8fae428" xlink:href="htgc-20240630.xsd#htgc_ExpensesAllocatedToAdviserSubsidiary1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_3ac8da4e-e926-48d9-accb-6daee938a514" xlink:to="loc_htgc_ExpensesAllocatedToAdviserSubsidiary1_553a6ecc-64f5-434d-9649-462dc8fae428" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_OperatingExpensesNet_a2372275-756c-4d00-816a-ea0738543fc1" xlink:href="htgc-20240630.xsd#htgc_OperatingExpensesNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_3ac8da4e-e926-48d9-accb-6daee938a514" xlink:to="loc_htgc_OperatingExpensesNet_a2372275-756c-4d00-816a-ea0738543fc1" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetInvestmentIncome_899a8265-d3c3-41b9-8551-35487a4c34b5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetInvestmentIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_3ac8da4e-e926-48d9-accb-6daee938a514" xlink:to="loc_us-gaap_NetInvestmentIncome_899a8265-d3c3-41b9-8551-35487a4c34b5" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyRealizedAndUnrealizedGainLossOnInvestmentAndForeignCurrencyAbstract_0bf01eac-f7e1-48d5-9517-1f5bf51410c7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentCompanyRealizedAndUnrealizedGainLossOnInvestmentAndForeignCurrencyAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_d61180cd-14b0-4cf8-9be7-baad305fd79a" xlink:to="loc_us-gaap_InvestmentCompanyRealizedAndUnrealizedGainLossOnInvestmentAndForeignCurrencyAbstract_0bf01eac-f7e1-48d5-9517-1f5bf51410c7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_NetRealizedGainLossAbstract_6ab66a32-b3c3-4801-b2f1-6843f70c7d0a" xlink:href="htgc-20240630.xsd#htgc_NetRealizedGainLossAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentCompanyRealizedAndUnrealizedGainLossOnInvestmentAndForeignCurrencyAbstract_0bf01eac-f7e1-48d5-9517-1f5bf51410c7" xlink:to="loc_htgc_NetRealizedGainLossAbstract_6ab66a32-b3c3-4801-b2f1-6843f70c7d0a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealizedInvestmentGainsLosses_4b79bd43-d4af-4b8a-bcf0-265844fb9780" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RealizedInvestmentGainsLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_NetRealizedGainLossAbstract_6ab66a32-b3c3-4801-b2f1-6843f70c7d0a" xlink:to="loc_us-gaap_RealizedInvestmentGainsLosses_4b79bd43-d4af-4b8a-bcf0-265844fb9780" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_RealizedInvestmentGainsLossAndGainLossOnExtinguishmentOfDebt_0e67e0e2-4efb-44e8-8ad5-5e9d3959cadf" xlink:href="htgc-20240630.xsd#htgc_RealizedInvestmentGainsLossAndGainLossOnExtinguishmentOfDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_NetRealizedGainLossAbstract_6ab66a32-b3c3-4801-b2f1-6843f70c7d0a" xlink:to="loc_htgc_RealizedInvestmentGainsLossAndGainLossOnExtinguishmentOfDebt_0e67e0e2-4efb-44e8-8ad5-5e9d3959cadf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_NetChangeInUnrealizedAppreciationDepreciationAbstract_fcf2c843-33d8-4157-8e1e-24136de1a648" xlink:href="htgc-20240630.xsd#htgc_NetChangeInUnrealizedAppreciationDepreciationAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentCompanyRealizedAndUnrealizedGainLossOnInvestmentAndForeignCurrencyAbstract_0bf01eac-f7e1-48d5-9517-1f5bf51410c7" xlink:to="loc_htgc_NetChangeInUnrealizedAppreciationDepreciationAbstract_fcf2c843-33d8-4157-8e1e-24136de1a648" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossOnInvestments_50972060-e79d-4a5e-afb4-ab17f95e645a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnrealizedGainLossOnInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_NetChangeInUnrealizedAppreciationDepreciationAbstract_fcf2c843-33d8-4157-8e1e-24136de1a648" xlink:to="loc_us-gaap_UnrealizedGainLossOnInvestments_50972060-e79d-4a5e-afb4-ab17f95e645a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyRealizedAndUnrealizedGainLossOnInvestmentAndForeignCurrency_e7015e02-db3c-461c-b0c9-cd9cf5496985" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentCompanyRealizedAndUnrealizedGainLossOnInvestmentAndForeignCurrency"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_NetChangeInUnrealizedAppreciationDepreciationAbstract_fcf2c843-33d8-4157-8e1e-24136de1a648" xlink:to="loc_us-gaap_InvestmentCompanyRealizedAndUnrealizedGainLossOnInvestmentAndForeignCurrency_e7015e02-db3c-461c-b0c9-cd9cf5496985" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_4432b9b1-b90c-4d9c-82ad-f7d5c7bf8c35" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_d61180cd-14b0-4cf8-9be7-baad305fd79a" xlink:to="loc_us-gaap_NetIncomeLoss_4432b9b1-b90c-4d9c-82ad-f7d5c7bf8c35" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyInvestmentIncomeLossFromOperationsPerShareAbstract_da2dd1a7-e2d9-4859-aaaf-5cd353c45dd0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentCompanyInvestmentIncomeLossFromOperationsPerShareAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_d61180cd-14b0-4cf8-9be7-baad305fd79a" xlink:to="loc_us-gaap_InvestmentCompanyInvestmentIncomeLossFromOperationsPerShareAbstract_da2dd1a7-e2d9-4859-aaaf-5cd353c45dd0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyInvestmentIncomeLossPerShare_69fe1f1c-73fb-43c8-bcf8-2c834a9d838e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentCompanyInvestmentIncomeLossPerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentCompanyInvestmentIncomeLossFromOperationsPerShareAbstract_da2dd1a7-e2d9-4859-aaaf-5cd353c45dd0" xlink:to="loc_us-gaap_InvestmentCompanyInvestmentIncomeLossPerShare_69fe1f1c-73fb-43c8-bcf8-2c834a9d838e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_EarningPerShareBasicAndDilutedAbstract_35411e31-7de3-4b0a-aa3d-7745f7d75983" xlink:href="htgc-20240630.xsd#htgc_EarningPerShareBasicAndDilutedAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_d61180cd-14b0-4cf8-9be7-baad305fd79a" xlink:to="loc_htgc_EarningPerShareBasicAndDilutedAbstract_35411e31-7de3-4b0a-aa3d-7745f7d75983" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_68a48717-9a7b-4d35-b7b1-6be50d7e2c43" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_EarningPerShareBasicAndDilutedAbstract_35411e31-7de3-4b0a-aa3d-7745f7d75983" xlink:to="loc_us-gaap_EarningsPerShareBasic_68a48717-9a7b-4d35-b7b1-6be50d7e2c43" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_f6022698-37dd-4d0d-ae6d-45da6f368bbf" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_EarningPerShareBasicAndDilutedAbstract_35411e31-7de3-4b0a-aa3d-7745f7d75983" xlink:to="loc_us-gaap_EarningsPerShareDiluted_f6022698-37dd-4d0d-ae6d-45da6f368bbf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_WeightedAverageNumberOfSharesOutstandingBasicAndDilutedAbstract_0106ec64-d8f6-4c52-9517-47127b4ab119" xlink:href="htgc-20240630.xsd#htgc_WeightedAverageNumberOfSharesOutstandingBasicAndDilutedAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_d61180cd-14b0-4cf8-9be7-baad305fd79a" xlink:to="loc_htgc_WeightedAverageNumberOfSharesOutstandingBasicAndDilutedAbstract_0106ec64-d8f6-4c52-9517-47127b4ab119" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_4bb4ad7e-e699-4be2-a489-93fb4f6ca8fb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_WeightedAverageNumberOfSharesOutstandingBasicAndDilutedAbstract_0106ec64-d8f6-4c52-9517-47127b4ab119" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_4bb4ad7e-e699-4be2-a489-93fb4f6ca8fb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_14a95b67-980d-4587-b9dc-cdd7722edfa4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_WeightedAverageNumberOfSharesOutstandingBasicAndDilutedAbstract_0106ec64-d8f6-4c52-9517-47127b4ab119" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_14a95b67-980d-4587-b9dc-cdd7722edfa4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DistributionsPaidPerCommonShareAbstract_2d5ff2bc-1b38-4c89-af84-122f8e423518" xlink:href="htgc-20240630.xsd#htgc_DistributionsPaidPerCommonShareAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_d61180cd-14b0-4cf8-9be7-baad305fd79a" xlink:to="loc_htgc_DistributionsPaidPerCommonShareAbstract_2d5ff2bc-1b38-4c89-af84-122f8e423518" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyDistributionToShareholdersPerShare_71270d37-0be0-4a49-8273-79d7f40d87a4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentCompanyDistributionToShareholdersPerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_DistributionsPaidPerCommonShareAbstract_2d5ff2bc-1b38-4c89-af84-122f8e423518" xlink:to="loc_us-gaap_InvestmentCompanyDistributionToShareholdersPerShare_71270d37-0be0-4a49-8273-79d7f40d87a4" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/CONSOLIDATEDSTATEMENTSOFCHANGESINNETASSETS" xlink:type="simple" xlink:href="htgc-20240630.xsd#CONSOLIDATEDSTATEMENTSOFCHANGESINNETASSETS"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/CONSOLIDATEDSTATEMENTSOFCHANGESINNETASSETS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_09bc3490-84fc-41d5-b58b-ef6faec82e9f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_e8bf4a7b-0857-45b1-9539-9af13902e836" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_09bc3490-84fc-41d5-b58b-ef6faec82e9f" xlink:to="loc_us-gaap_StatementTable_e8bf4a7b-0857-45b1-9539-9af13902e836" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_e6d7b71a-7da4-4c5a-9ee4-82a6db58c5e0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_e8bf4a7b-0857-45b1-9539-9af13902e836" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_e6d7b71a-7da4-4c5a-9ee4-82a6db58c5e0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_e6d7b71a-7da4-4c5a-9ee4-82a6db58c5e0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_e6d7b71a-7da4-4c5a-9ee4-82a6db58c5e0" xlink:to="loc_us-gaap_EquityComponentDomain_e6d7b71a-7da4-4c5a-9ee4-82a6db58c5e0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_b7911de0-703a-4214-a934-f0970a0a6b48" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_e6d7b71a-7da4-4c5a-9ee4-82a6db58c5e0" xlink:to="loc_us-gaap_EquityComponentDomain_b7911de0-703a-4214-a934-f0970a0a6b48" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_95ef3808-6916-4e42-bcef-89cb169037b7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_b7911de0-703a-4214-a934-f0970a0a6b48" xlink:to="loc_us-gaap_CommonStockMember_95ef3808-6916-4e42-bcef-89cb169037b7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CapitalInExcessOfParValueMember_3a376ca4-191c-42f6-9c0d-8759e47a1d95" xlink:href="htgc-20240630.xsd#htgc_CapitalInExcessOfParValueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_b7911de0-703a-4214-a934-f0970a0a6b48" xlink:to="loc_htgc_CapitalInExcessOfParValueMember_3a376ca4-191c-42f6-9c0d-8759e47a1d95" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DistributableEarningsLossMember_773fff6b-d672-4f8b-acdb-c80eca718747" xlink:href="htgc-20240630.xsd#htgc_DistributableEarningsLossMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_b7911de0-703a-4214-a934-f0970a0a6b48" xlink:to="loc_htgc_DistributableEarningsLossMember_773fff6b-d672-4f8b-acdb-c80eca718747" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e640c798-8a4d-4657-a594-1ddd4a10f21d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_09bc3490-84fc-41d5-b58b-ef6faec82e9f" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e640c798-8a4d-4657-a594-1ddd4a10f21d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_9be8c50d-443d-4762-89b1-bcf2adaeef03" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e640c798-8a4d-4657-a594-1ddd4a10f21d" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_9be8c50d-443d-4762-89b1-bcf2adaeef03" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_d14b263a-5b06-487b-8d95-2d3daedeb0b8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e640c798-8a4d-4657-a594-1ddd4a10f21d" xlink:to="loc_us-gaap_StockholdersEquity_d14b263a-5b06-487b-8d95-2d3daedeb0b8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_a1b37253-a1a4-4009-a531-7a9d50cd6e6f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e640c798-8a4d-4657-a594-1ddd4a10f21d" xlink:to="loc_us-gaap_NetIncomeLoss_a1b37253-a1a4-4009-a531-7a9d50cd6e6f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_2238baa2-4689-4b1c-949d-4da18b2a8dce" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e640c798-8a4d-4657-a594-1ddd4a10f21d" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_2238baa2-4689-4b1c-949d-4da18b2a8dce" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_0fbda6a0-4204-4e6f-a576-5b77658716ae" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e640c798-8a4d-4657-a594-1ddd4a10f21d" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_0fbda6a0-4204-4e6f-a576-5b77658716ae" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_c5f3197b-c677-4d40-b336-87a40a654b6e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e640c798-8a4d-4657-a594-1ddd4a10f21d" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_c5f3197b-c677-4d40-b336-87a40a654b6e" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures_a794eef6-de9a-4c32-9aa5-5cd6d2fe55cf" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e640c798-8a4d-4657-a594-1ddd4a10f21d" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures_a794eef6-de9a-4c32-9aa5-5cd6d2fe55cf" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_dada37b6-9619-4440-9b1b-3aca947327ad" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e640c798-8a4d-4657-a594-1ddd4a10f21d" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_dada37b6-9619-4440-9b1b-3aca947327ad" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_6baa8aea-cde0-4c00-b314-0b1669b3cfd9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e640c798-8a4d-4657-a594-1ddd4a10f21d" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_6baa8aea-cde0-4c00-b314-0b1669b3cfd9" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan_a2f7d6ed-b84a-4b70-831d-49c2338c99c6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e640c798-8a4d-4657-a594-1ddd4a10f21d" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan_a2f7d6ed-b84a-4b70-831d-49c2338c99c6" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan_fcff59ad-7e57-48c2-b7e9-2c42dca7eae4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e640c798-8a4d-4657-a594-1ddd4a10f21d" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueDividendReinvestmentPlan_fcff59ad-7e57-48c2-b7e9-2c42dca7eae4" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyDividendDistribution_4d1510d9-45b9-4362-a21a-bf5a379a87d8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentCompanyDividendDistribution"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e640c798-8a4d-4657-a594-1ddd4a10f21d" xlink:to="loc_us-gaap_InvestmentCompanyDividendDistribution_4d1510d9-45b9-4362-a21a-bf5a379a87d8" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_ef119263-ed4a-46dc-b3fd-2c4741c43fbe" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_e640c798-8a4d-4657-a594-1ddd4a10f21d" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_ef119263-ed4a-46dc-b3fd-2c4741c43fbe" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_3b555035-23e7-4404-b7d1-0e7a2462d70b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_0a7ee468-7c85-45ee-9eac-c2fd4a6623f6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquity"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWSunauditedParenthetical" xlink:type="simple" xlink:href="htgc-20240630.xsd#CONSOLIDATEDSTATEMENTSOFCASHFLOWSunauditedParenthetical"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWSunauditedParenthetical" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_f5da4d0a-cf99-4c27-a22c-7f4fc750a838" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_971385b9-c609-4915-9a24-1a091cfc8ff2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_f5da4d0a-cf99-4c27-a22c-7f4fc750a838" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_971385b9-c609-4915-9a24-1a091cfc8ff2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_464cde08-ca61-4f6f-8c72-b76e4ae1d736" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_971385b9-c609-4915-9a24-1a091cfc8ff2" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_464cde08-ca61-4f6f-8c72-b76e4ae1d736" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_464cde08-ca61-4f6f-8c72-b76e4ae1d736_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_464cde08-ca61-4f6f-8c72-b76e4ae1d736" xlink:to="loc_us-gaap_RelatedPartyDomain_464cde08-ca61-4f6f-8c72-b76e4ae1d736_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_9e67f923-c882-4118-aaea-bae841e24e3a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_464cde08-ca61-4f6f-8c72-b76e4ae1d736" xlink:to="loc_us-gaap_RelatedPartyDomain_9e67f923-c882-4118-aaea-bae841e24e3a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_AdvisorFundsMember_f5281f12-5607-4cca-84be-1ee118cbc636" xlink:href="htgc-20240630.xsd#htgc_AdvisorFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_9e67f923-c882-4118-aaea-bae841e24e3a" xlink:to="loc_htgc_AdvisorFundsMember_f5281f12-5607-4cca-84be-1ee118cbc636" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_AdviserSubsidiaryInvestmentFunding_7d1c63a0-a7f4-4e9e-90fa-b57a5073059a" xlink:href="htgc-20240630.xsd#htgc_AdviserSubsidiaryInvestmentFunding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_f5da4d0a-cf99-4c27-a22c-7f4fc750a838" xlink:to="loc_htgc_AdviserSubsidiaryInvestmentFunding_7d1c63a0-a7f4-4e9e-90fa-b57a5073059a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationOtherLongtermIncentivePlansRequisiteServicePeriodRecognition_bd2e3e73-e6fe-404c-b8f0-9a327e054718" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationOtherLongtermIncentivePlansRequisiteServicePeriodRecognition"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_f5da4d0a-cf99-4c27-a22c-7f4fc750a838" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationOtherLongtermIncentivePlansRequisiteServicePeriodRecognition_bd2e3e73-e6fe-404c-b8f0-9a327e054718" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_21f84da4-3ba2-4dad-83f2-4d97ec58e69b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_f5da4d0a-cf99-4c27-a22c-7f4fc750a838" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_21f84da4-3ba2-4dad-83f2-4d97ec58e69b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCash_601014f7-f38e-4247-ba07-2ec9082577e3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestrictedCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_f5da4d0a-cf99-4c27-a22c-7f4fc750a838" xlink:to="loc_us-gaap_RestrictedCash_601014f7-f38e-4247-ba07-2ec9082577e3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_7cfdcb3f-4e40-47cc-9f7b-a11faf80e046" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_f5da4d0a-cf99-4c27-a22c-7f4fc750a838" xlink:to="loc_us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_7cfdcb3f-4e40-47cc-9f7b-a11faf80e046" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/CONSOLIDATEDSCHEDULEOFINVESTMENTS" xlink:type="simple" xlink:href="htgc-20240630.xsd#CONSOLIDATEDSCHEDULEOFINVESTMENTS"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/CONSOLIDATEDSCHEDULEOFINVESTMENTS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SummaryOfInvestmentHoldingsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SummaryOfInvestmentHoldingsTable_d8992ffd-2d76-4f17-b14b-834e23dbdeb6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SummaryOfInvestmentHoldingsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_us-gaap_SummaryOfInvestmentHoldingsTable_d8992ffd-2d76-4f17-b14b-834e23dbdeb6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIdentifierAxis_2be10554-7bc2-46b5-82cd-926bae42589b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentIdentifierAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsTable_d8992ffd-2d76-4f17-b14b-834e23dbdeb6" xlink:to="loc_us-gaap_InvestmentIdentifierAxis_2be10554-7bc2-46b5-82cd-926bae42589b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_2bd04cb0-9e1f-4b88-9279-c450db60deb9" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsTable_d8992ffd-2d76-4f17-b14b-834e23dbdeb6" xlink:to="loc_srt_RangeAxis_2bd04cb0-9e1f-4b88-9279-c450db60deb9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_2bd04cb0-9e1f-4b88-9279-c450db60deb9_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_2bd04cb0-9e1f-4b88-9279-c450db60deb9" xlink:to="loc_srt_RangeMember_2bd04cb0-9e1f-4b88-9279-c450db60deb9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_847f71cb-7b41-4fb4-af54-9ad92074d0e0" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_2bd04cb0-9e1f-4b88-9279-c450db60deb9" xlink:to="loc_srt_RangeMember_847f71cb-7b41-4fb4-af54-9ad92074d0e0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_8a7a1c18-342a-4688-bfef-cd43b58e7cfc" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_847f71cb-7b41-4fb4-af54-9ad92074d0e0" xlink:to="loc_srt_MinimumMember_8a7a1c18-342a-4688-bfef-cd43b58e7cfc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_dba315d8-aa5f-4de3-9c05-eda697635682" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_847f71cb-7b41-4fb4-af54-9ad92074d0e0" xlink:to="loc_srt_MaximumMember_dba315d8-aa5f-4de3-9c05-eda697635682" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedPercentOfNetAssets_98f8db60-e9ca-4b4d-8def-f65a8ec5433f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedPercentOfNetAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_us-gaap_InvestmentOwnedPercentOfNetAssets_98f8db60-e9ca-4b4d-8def-f65a8ec5433f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_InvestmentsMaturityMonthAndYear_f3c4d2cf-aee0-4fe5-8294-23e9432e6ec2" xlink:href="htgc-20240630.xsd#htgc_InvestmentsMaturityMonthAndYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_htgc_InvestmentsMaturityMonthAndYear_f3c4d2cf-aee0-4fe5-8294-23e9432e6ec2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentBasisSpreadVariableRate_8ddd0188-eed6-42cd-a616-d48c1c72aa8b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentBasisSpreadVariableRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_us-gaap_InvestmentBasisSpreadVariableRate_8ddd0188-eed6-42cd-a616-d48c1c72aa8b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentInterestRateFloor_59bd12fd-bd96-43d9-88b3-eb4490bb2963" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentInterestRateFloor"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_us-gaap_InvestmentInterestRateFloor_59bd12fd-bd96-43d9-88b3-eb4490bb2963" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_InvestmentInterestRateCap_3e329f0b-9ef2-4b44-b4cd-30cbc6451fa4" xlink:href="htgc-20240630.xsd#htgc_InvestmentInterestRateCap"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_htgc_InvestmentInterestRateCap_3e329f0b-9ef2-4b44-b4cd-30cbc6451fa4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentInterestRatePaidInKind_6457a345-5d53-4581-b5ed-2905302c2e56" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentInterestRatePaidInKind"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_us-gaap_InvestmentInterestRatePaidInKind_6457a345-5d53-4581-b5ed-2905302c2e56" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentInterestRatePaidInCash_ae093525-ba7a-477e-bb6f-14ba6ec59631" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentInterestRatePaidInCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_us-gaap_InvestmentInterestRatePaidInCash_ae093525-ba7a-477e-bb6f-14ba6ec59631" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_InvestmentExitFee_25ceea57-f1b7-4406-bcea-7436ff10dc9d" xlink:href="htgc-20240630.xsd#htgc_InvestmentExitFee"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_htgc_InvestmentExitFee_25ceea57-f1b7-4406-bcea-7436ff10dc9d" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedBalancePrincipalAmount_54491066-6634-46f2-8f28-c47ce90cddcc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedBalancePrincipalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_us-gaap_InvestmentOwnedBalancePrincipalAmount_54491066-6634-46f2-8f28-c47ce90cddcc" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtCost_d9144d72-1818-4edb-84d8-7dcbf775e861" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedAtCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_us-gaap_InvestmentOwnedAtCost_d9144d72-1818-4edb-84d8-7dcbf775e861" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtFairValue_b7bbc4f9-669b-4557-82cd-78b910c3e0f7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_us-gaap_InvestmentOwnedAtFairValue_b7bbc4f9-669b-4557-82cd-78b910c3e0f7" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_InvestmentsOwnedAcquisitionDate_5a91292a-e0f8-47f7-bd3b-879114c6fc1a" xlink:href="htgc-20240630.xsd#htgc_InvestmentsOwnedAcquisitionDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_htgc_InvestmentsOwnedAcquisitionDate_5a91292a-e0f8-47f7-bd3b-879114c6fc1a" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedBalanceShares_77033e60-541f-48f8-be5e-55e13a8f542d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedBalanceShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_us-gaap_InvestmentOwnedBalanceShares_77033e60-541f-48f8-be5e-55e13a8f542d" xlink:type="arc" order="12"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/CONSOLIDATEDSCHEDULEOFINVESTMENTS_1" xlink:type="simple" xlink:href="htgc-20240630.xsd#CONSOLIDATEDSCHEDULEOFINVESTMENTS_1"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/CONSOLIDATEDSCHEDULEOFINVESTMENTS_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SummaryOfInvestmentHoldingsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SummaryOfInvestmentHoldingsTable_d8992ffd-2d76-4f17-b14b-834e23dbdeb6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SummaryOfInvestmentHoldingsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_us-gaap_SummaryOfInvestmentHoldingsTable_d8992ffd-2d76-4f17-b14b-834e23dbdeb6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_2bd04cb0-9e1f-4b88-9279-c450db60deb9" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsTable_d8992ffd-2d76-4f17-b14b-834e23dbdeb6" xlink:to="loc_srt_RangeAxis_2bd04cb0-9e1f-4b88-9279-c450db60deb9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_2bd04cb0-9e1f-4b88-9279-c450db60deb9_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_2bd04cb0-9e1f-4b88-9279-c450db60deb9" xlink:to="loc_srt_RangeMember_2bd04cb0-9e1f-4b88-9279-c450db60deb9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_847f71cb-7b41-4fb4-af54-9ad92074d0e0" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_2bd04cb0-9e1f-4b88-9279-c450db60deb9" xlink:to="loc_srt_RangeMember_847f71cb-7b41-4fb4-af54-9ad92074d0e0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_8a7a1c18-342a-4688-bfef-cd43b58e7cfc" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_847f71cb-7b41-4fb4-af54-9ad92074d0e0" xlink:to="loc_srt_MinimumMember_8a7a1c18-342a-4688-bfef-cd43b58e7cfc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_dba315d8-aa5f-4de3-9c05-eda697635682" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_847f71cb-7b41-4fb4-af54-9ad92074d0e0" xlink:to="loc_srt_MaximumMember_dba315d8-aa5f-4de3-9c05-eda697635682" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedPercentOfNetAssets_98f8db60-e9ca-4b4d-8def-f65a8ec5433f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedPercentOfNetAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_us-gaap_InvestmentOwnedPercentOfNetAssets_98f8db60-e9ca-4b4d-8def-f65a8ec5433f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_InvestmentsMaturityMonthAndYear_f3c4d2cf-aee0-4fe5-8294-23e9432e6ec2" xlink:href="htgc-20240630.xsd#htgc_InvestmentsMaturityMonthAndYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_htgc_InvestmentsMaturityMonthAndYear_f3c4d2cf-aee0-4fe5-8294-23e9432e6ec2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentBasisSpreadVariableRate_8ddd0188-eed6-42cd-a616-d48c1c72aa8b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentBasisSpreadVariableRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_us-gaap_InvestmentBasisSpreadVariableRate_8ddd0188-eed6-42cd-a616-d48c1c72aa8b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentInterestRateFloor_59bd12fd-bd96-43d9-88b3-eb4490bb2963" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentInterestRateFloor"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_us-gaap_InvestmentInterestRateFloor_59bd12fd-bd96-43d9-88b3-eb4490bb2963" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_InvestmentInterestRateCap_3e329f0b-9ef2-4b44-b4cd-30cbc6451fa4" xlink:href="htgc-20240630.xsd#htgc_InvestmentInterestRateCap"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_htgc_InvestmentInterestRateCap_3e329f0b-9ef2-4b44-b4cd-30cbc6451fa4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentInterestRatePaidInKind_6457a345-5d53-4581-b5ed-2905302c2e56" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentInterestRatePaidInKind"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_us-gaap_InvestmentInterestRatePaidInKind_6457a345-5d53-4581-b5ed-2905302c2e56" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentInterestRatePaidInCash_ae093525-ba7a-477e-bb6f-14ba6ec59631" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentInterestRatePaidInCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_us-gaap_InvestmentInterestRatePaidInCash_ae093525-ba7a-477e-bb6f-14ba6ec59631" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_InvestmentExitFee_25ceea57-f1b7-4406-bcea-7436ff10dc9d" xlink:href="htgc-20240630.xsd#htgc_InvestmentExitFee"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_htgc_InvestmentExitFee_25ceea57-f1b7-4406-bcea-7436ff10dc9d" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedBalancePrincipalAmount_54491066-6634-46f2-8f28-c47ce90cddcc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedBalancePrincipalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_us-gaap_InvestmentOwnedBalancePrincipalAmount_54491066-6634-46f2-8f28-c47ce90cddcc" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtCost_d9144d72-1818-4edb-84d8-7dcbf775e861" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedAtCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_us-gaap_InvestmentOwnedAtCost_d9144d72-1818-4edb-84d8-7dcbf775e861" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtFairValue_b7bbc4f9-669b-4557-82cd-78b910c3e0f7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_us-gaap_InvestmentOwnedAtFairValue_b7bbc4f9-669b-4557-82cd-78b910c3e0f7" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_InvestmentsOwnedAcquisitionDate_5a91292a-e0f8-47f7-bd3b-879114c6fc1a" xlink:href="htgc-20240630.xsd#htgc_InvestmentsOwnedAcquisitionDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_htgc_InvestmentsOwnedAcquisitionDate_5a91292a-e0f8-47f7-bd3b-879114c6fc1a" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedBalanceShares_77033e60-541f-48f8-be5e-55e13a8f542d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedBalanceShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_8d8e21fc-afa4-4395-8319-58e6aaf8310a" xlink:to="loc_us-gaap_InvestmentOwnedBalanceShares_77033e60-541f-48f8-be5e-55e13a8f542d" xlink:type="arc" order="12"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/CONSOLIDATEDSCHEDULEOFINVESTMENTSForwardForeignCurrencyExchangeContracts" xlink:type="simple" xlink:href="htgc-20240630.xsd#CONSOLIDATEDSCHEDULEOFINVESTMENTSForwardForeignCurrencyExchangeContracts"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/CONSOLIDATEDSCHEDULEOFINVESTMENTSForwardForeignCurrencyExchangeContracts" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentsLineItems_d55981ce-e1aa-4b2d-bbea-ec0ce61f08af" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfInvestmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentsTable_b7d933ef-5f40-4a2f-a95e-e6cd57890326" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfInvestmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_d55981ce-e1aa-4b2d-bbea-ec0ce61f08af" xlink:to="loc_us-gaap_ScheduleOfInvestmentsTable_b7d933ef-5f40-4a2f-a95e-e6cd57890326" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OpenForwardForeignCurrencyContractIdentifierAxis_dce8a747-4320-42bc-926f-99cb2181e72e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OpenForwardForeignCurrencyContractIdentifierAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentsTable_b7d933ef-5f40-4a2f-a95e-e6cd57890326" xlink:to="loc_us-gaap_OpenForwardForeignCurrencyContractIdentifierAxis_dce8a747-4320-42bc-926f-99cb2181e72e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedPercentOfNetAssets_2861b1aa-67ca-45d0-a311-5cbd0011805c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedPercentOfNetAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_d55981ce-e1aa-4b2d-bbea-ec0ce61f08af" xlink:to="loc_us-gaap_InvestmentOwnedPercentOfNetAssets_2861b1aa-67ca-45d0-a311-5cbd0011805c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeMaturityDates_1a0d3f8e-110b-4b5a-a943-e42d57e0d0cd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeMaturityDates"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_d55981ce-e1aa-4b2d-bbea-ec0ce61f08af" xlink:to="loc_us-gaap_DerivativeMaturityDates_1a0d3f8e-110b-4b5a-a943-e42d57e0d0cd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetNotionalAmount_300796be-af1f-45b0-a31f-50ac18af120b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeAssetNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_d55981ce-e1aa-4b2d-bbea-ec0ce61f08af" xlink:to="loc_us-gaap_DerivativeAssetNotionalAmount_300796be-af1f-45b0-a31f-50ac18af120b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityNotionalAmount_42aff9e7-af57-44b3-8aa0-ca6d9f81ae7c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeLiabilityNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_d55981ce-e1aa-4b2d-bbea-ec0ce61f08af" xlink:to="loc_us-gaap_DerivativeLiabilityNotionalAmount_42aff9e7-af57-44b3-8aa0-ca6d9f81ae7c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CumulativeUnrealizedGainLossOnDerivatives_557aea5c-bccb-41b0-a704-a3b5b992cf2a" xlink:href="htgc-20240630.xsd#htgc_CumulativeUnrealizedGainLossOnDerivatives"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_d55981ce-e1aa-4b2d-bbea-ec0ce61f08af" xlink:to="loc_htgc_CumulativeUnrealizedGainLossOnDerivatives_557aea5c-bccb-41b0-a704-a3b5b992cf2a" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/CONSOLIDATEDSCHEDULEOFINVESTMENTSForwardForeignCurrencyExchangeContracts_1" xlink:type="simple" xlink:href="htgc-20240630.xsd#CONSOLIDATEDSCHEDULEOFINVESTMENTSForwardForeignCurrencyExchangeContracts_1"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/CONSOLIDATEDSCHEDULEOFINVESTMENTSForwardForeignCurrencyExchangeContracts_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentsLineItems_d55981ce-e1aa-4b2d-bbea-ec0ce61f08af" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfInvestmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentsTable_b7d933ef-5f40-4a2f-a95e-e6cd57890326" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfInvestmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_d55981ce-e1aa-4b2d-bbea-ec0ce61f08af" xlink:to="loc_us-gaap_ScheduleOfInvestmentsTable_b7d933ef-5f40-4a2f-a95e-e6cd57890326" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedPercentOfNetAssets_2861b1aa-67ca-45d0-a311-5cbd0011805c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedPercentOfNetAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_d55981ce-e1aa-4b2d-bbea-ec0ce61f08af" xlink:to="loc_us-gaap_InvestmentOwnedPercentOfNetAssets_2861b1aa-67ca-45d0-a311-5cbd0011805c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeMaturityDates_1a0d3f8e-110b-4b5a-a943-e42d57e0d0cd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeMaturityDates"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_d55981ce-e1aa-4b2d-bbea-ec0ce61f08af" xlink:to="loc_us-gaap_DerivativeMaturityDates_1a0d3f8e-110b-4b5a-a943-e42d57e0d0cd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetNotionalAmount_300796be-af1f-45b0-a31f-50ac18af120b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeAssetNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_d55981ce-e1aa-4b2d-bbea-ec0ce61f08af" xlink:to="loc_us-gaap_DerivativeAssetNotionalAmount_300796be-af1f-45b0-a31f-50ac18af120b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityNotionalAmount_42aff9e7-af57-44b3-8aa0-ca6d9f81ae7c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeLiabilityNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_d55981ce-e1aa-4b2d-bbea-ec0ce61f08af" xlink:to="loc_us-gaap_DerivativeLiabilityNotionalAmount_42aff9e7-af57-44b3-8aa0-ca6d9f81ae7c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CumulativeUnrealizedGainLossOnDerivatives_557aea5c-bccb-41b0-a704-a3b5b992cf2a" xlink:href="htgc-20240630.xsd#htgc_CumulativeUnrealizedGainLossOnDerivatives"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_d55981ce-e1aa-4b2d-bbea-ec0ce61f08af" xlink:to="loc_htgc_CumulativeUnrealizedGainLossOnDerivatives_557aea5c-bccb-41b0-a704-a3b5b992cf2a" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/CONSOLIDATEDSCHEDULEOFINVESTMENTSParenthetical" xlink:type="simple" xlink:href="htgc-20240630.xsd#CONSOLIDATEDSCHEDULEOFINVESTMENTSParenthetical"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/CONSOLIDATEDSCHEDULEOFINVESTMENTSParenthetical" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_htgc_InvestmentHoldingLineItems_3a64cccb-e906-49fe-995c-17a7bd720899" xlink:href="htgc-20240630.xsd#htgc_InvestmentHoldingLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_InvestmentHoldingTable_e6338efa-512d-4783-a0d3-15ae6c5c9336" xlink:href="htgc-20240630.xsd#htgc_InvestmentHoldingTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_htgc_InvestmentHoldingLineItems_3a64cccb-e906-49fe-995c-17a7bd720899" xlink:to="loc_htgc_InvestmentHoldingTable_e6338efa-512d-4783-a0d3-15ae6c5c9336" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_d58a67d9-3ab8-4135-bfaa-ca83bc67d78c" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_htgc_InvestmentHoldingTable_e6338efa-512d-4783-a0d3-15ae6c5c9336" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_d58a67d9-3ab8-4135-bfaa-ca83bc67d78c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_d58a67d9-3ab8-4135-bfaa-ca83bc67d78c_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_d58a67d9-3ab8-4135-bfaa-ca83bc67d78c" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_d58a67d9-3ab8-4135-bfaa-ca83bc67d78c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_df6736b9-daa2-4430-b0ec-5bfd48cfdee8" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_d58a67d9-3ab8-4135-bfaa-ca83bc67d78c" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_df6736b9-daa2-4430-b0ec-5bfd48cfdee8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_BlackCrowAIIncMember_1a3d6843-32d4-435b-ad96-4cf78269a3d1" xlink:href="htgc-20240630.xsd#htgc_BlackCrowAIIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_df6736b9-daa2-4430-b0ec-5bfd48cfdee8" xlink:to="loc_htgc_BlackCrowAIIncMember_1a3d6843-32d4-435b-ad96-4cf78269a3d1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_PhathomPharmaceuticalsIncMember_71bced32-99ce-4acf-9c8c-3c63b6755d86" xlink:href="htgc-20240630.xsd#htgc_PhathomPharmaceuticalsIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_df6736b9-daa2-4430-b0ec-5bfd48cfdee8" xlink:to="loc_htgc_PhathomPharmaceuticalsIncMember_71bced32-99ce-4acf-9c8c-3c63b6755d86" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_0c92fb96-4946-4b36-a74d-f4490d489d4c" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_htgc_InvestmentHoldingTable_e6338efa-512d-4783-a0d3-15ae6c5c9336" xlink:to="loc_srt_StatementGeographicalAxis_0c92fb96-4946-4b36-a74d-f4490d489d4c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_0c92fb96-4946-4b36-a74d-f4490d489d4c_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_0c92fb96-4946-4b36-a74d-f4490d489d4c" xlink:to="loc_srt_SegmentGeographicalDomain_0c92fb96-4946-4b36-a74d-f4490d489d4c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_21d7bbfb-b264-419c-9c77-c9e55c1dcb38" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_0c92fb96-4946-4b36-a74d-f4490d489d4c" xlink:to="loc_srt_SegmentGeographicalDomain_21d7bbfb-b264-419c-9c77-c9e55c1dcb38" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_RoyaltyContractMember_276be57c-15b4-4758-963c-e73363ef02e2" xlink:href="htgc-20240630.xsd#htgc_RoyaltyContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_21d7bbfb-b264-419c-9c77-c9e55c1dcb38" xlink:to="loc_htgc_RoyaltyContractMember_276be57c-15b4-4758-963c-e73363ef02e2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_56c92551-c15e-48fb-9a4b-6ebeaa5efe78" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_htgc_InvestmentHoldingTable_e6338efa-512d-4783-a0d3-15ae6c5c9336" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_56c92551-c15e-48fb-9a4b-6ebeaa5efe78" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_56c92551-c15e-48fb-9a4b-6ebeaa5efe78_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_56c92551-c15e-48fb-9a4b-6ebeaa5efe78" xlink:to="loc_us-gaap_EquityComponentDomain_56c92551-c15e-48fb-9a4b-6ebeaa5efe78_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_e9f252a7-8e73-4e86-ab3e-66d3bc3af153" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_56c92551-c15e-48fb-9a4b-6ebeaa5efe78" xlink:to="loc_us-gaap_EquityComponentDomain_e9f252a7-8e73-4e86-ab3e-66d3bc3af153" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_18e95331-f74a-42d5-a2b0-195c5e0becff" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_e9f252a7-8e73-4e86-ab3e-66d3bc3af153" xlink:to="loc_us-gaap_CommonStockMember_18e95331-f74a-42d5-a2b0-195c5e0becff" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantMember_ed776f10-91b7-432e-8793-a2f05ed4a57e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_WarrantMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_e9f252a7-8e73-4e86-ab3e-66d3bc3af153" xlink:to="loc_us-gaap_WarrantMember_ed776f10-91b7-432e-8793-a2f05ed4a57e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_0fb6a014-5d7a-43d9-89cc-a3ae1655bd0c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_htgc_InvestmentHoldingTable_e6338efa-512d-4783-a0d3-15ae6c5c9336" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_0fb6a014-5d7a-43d9-89cc-a3ae1655bd0c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0fb6a014-5d7a-43d9-89cc-a3ae1655bd0c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_0fb6a014-5d7a-43d9-89cc-a3ae1655bd0c" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0fb6a014-5d7a-43d9-89cc-a3ae1655bd0c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_687cecd6-54a6-4959-884e-3feb4a98af2e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_0fb6a014-5d7a-43d9-89cc-a3ae1655bd0c" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_687cecd6-54a6-4959-884e-3feb4a98af2e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_d56f04bc-6a13-4e7d-8c37-86f037dbf54e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_687cecd6-54a6-4959-884e-3feb4a98af2e" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_d56f04bc-6a13-4e7d-8c37-86f037dbf54e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_56f82f45-e5be-451d-83f1-0f7ce8178af2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_687cecd6-54a6-4959-884e-3feb4a98af2e" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_56f82f45-e5be-451d-83f1-0f7ce8178af2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_72bfc2e8-080c-47cd-8d5f-d07c3f3b8279" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_htgc_InvestmentHoldingTable_e6338efa-512d-4783-a0d3-15ae6c5c9336" xlink:to="loc_us-gaap_FinancialInstrumentAxis_72bfc2e8-080c-47cd-8d5f-d07c3f3b8279" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_72bfc2e8-080c-47cd-8d5f-d07c3f3b8279_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_72bfc2e8-080c-47cd-8d5f-d07c3f3b8279" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_72bfc2e8-080c-47cd-8d5f-d07c3f3b8279_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_559e9863-bef9-4b65-b055-d456807405f4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_72bfc2e8-080c-47cd-8d5f-d07c3f3b8279" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_559e9863-bef9-4b65-b055-d456807405f4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_OneMonthSOFRMember_d959eebf-4c5b-4e96-a57b-bc6c2591dfe5" xlink:href="htgc-20240630.xsd#htgc_OneMonthSOFRMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_559e9863-bef9-4b65-b055-d456807405f4" xlink:to="loc_htgc_OneMonthSOFRMember_d959eebf-4c5b-4e96-a57b-bc6c2591dfe5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ThreeMonthSOFRMember_06e114c7-e52b-4885-9d34-b3caeaff4c9f" xlink:href="htgc-20240630.xsd#htgc_ThreeMonthSOFRMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_559e9863-bef9-4b65-b055-d456807405f4" xlink:to="loc_htgc_ThreeMonthSOFRMember_06e114c7-e52b-4885-9d34-b3caeaff4c9f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SixMonthSOFRMember_8392838d-d9c8-4335-be18-386e43fa8606" xlink:href="htgc-20240630.xsd#htgc_SixMonthSOFRMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_559e9863-bef9-4b65-b055-d456807405f4" xlink:to="loc_htgc_SixMonthSOFRMember_8392838d-d9c8-4335-be18-386e43fa8606" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_6d137841-967c-4878-b478-c1a03ee88db0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_htgc_InvestmentHoldingTable_e6338efa-512d-4783-a0d3-15ae6c5c9336" xlink:to="loc_us-gaap_DebtInstrumentAxis_6d137841-967c-4878-b478-c1a03ee88db0" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_6d137841-967c-4878-b478-c1a03ee88db0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_6d137841-967c-4878-b478-c1a03ee88db0" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_6d137841-967c-4878-b478-c1a03ee88db0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_a68815a9-78cc-404a-b4f4-39eb52e79b5e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_6d137841-967c-4878-b478-c1a03ee88db0" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_a68815a9-78cc-404a-b4f4-39eb52e79b5e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_PromissoryNotesMember_0d4b360c-c0e6-4dff-996f-6cc9390c8c21" xlink:href="htgc-20240630.xsd#htgc_PromissoryNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_a68815a9-78cc-404a-b4f4-39eb52e79b5e" xlink:to="loc_htgc_PromissoryNotesMember_0d4b360c-c0e6-4dff-996f-6cc9390c8c21" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentBasisSpreadVariableRate_bb165158-ebe3-4a8c-a688-e31fb74ef44b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentBasisSpreadVariableRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_InvestmentHoldingLineItems_3a64cccb-e906-49fe-995c-17a7bd720899" xlink:to="loc_us-gaap_InvestmentBasisSpreadVariableRate_bb165158-ebe3-4a8c-a688-e31fb74ef44b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentInterestRate_40c07b5d-75a3-4e91-b372-62e0b52deb8e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_InvestmentHoldingLineItems_3a64cccb-e906-49fe-995c-17a7bd720899" xlink:to="loc_us-gaap_InvestmentInterestRate_40c07b5d-75a3-4e91-b372-62e0b52deb8e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxBasisOfInvestmentsGrossUnrealizedAppreciation_01083a55-9ffc-473a-bf19-ac3440d3ddd9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TaxBasisOfInvestmentsGrossUnrealizedAppreciation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_InvestmentHoldingLineItems_3a64cccb-e906-49fe-995c-17a7bd720899" xlink:to="loc_us-gaap_TaxBasisOfInvestmentsGrossUnrealizedAppreciation_01083a55-9ffc-473a-bf19-ac3440d3ddd9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxBasisOfInvestmentsGrossUnrealizedDepreciation_45ece8eb-86e4-4c46-bd19-babb7d7eaa39" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TaxBasisOfInvestmentsGrossUnrealizedDepreciation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_InvestmentHoldingLineItems_3a64cccb-e906-49fe-995c-17a7bd720899" xlink:to="loc_us-gaap_TaxBasisOfInvestmentsGrossUnrealizedDepreciation_45ece8eb-86e4-4c46-bd19-babb7d7eaa39" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxBasisOfInvestmentsUnrealizedAppreciationDepreciationNet_163cb412-c1f8-4816-a897-ac5ad5cba071" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TaxBasisOfInvestmentsUnrealizedAppreciationDepreciationNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_InvestmentHoldingLineItems_3a64cccb-e906-49fe-995c-17a7bd720899" xlink:to="loc_us-gaap_TaxBasisOfInvestmentsUnrealizedAppreciationDepreciationNet_163cb412-c1f8-4816-a897-ac5ad5cba071" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxBasisOfInvestmentsCostForIncomeTaxPurposes_14c4fc54-cddd-4e61-8676-54eac02bdd22" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TaxBasisOfInvestmentsCostForIncomeTaxPurposes"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_InvestmentHoldingLineItems_3a64cccb-e906-49fe-995c-17a7bd720899" xlink:to="loc_us-gaap_TaxBasisOfInvestmentsCostForIncomeTaxPurposes_14c4fc54-cddd-4e61-8676-54eac02bdd22" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_NumberOfPubliclyTradedCompanies_4a36ef55-8008-485d-8ab7-567d9ef25fd8" xlink:href="htgc-20240630.xsd#htgc_NumberOfPubliclyTradedCompanies"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_InvestmentHoldingLineItems_3a64cccb-e906-49fe-995c-17a7bd720899" xlink:to="loc_htgc_NumberOfPubliclyTradedCompanies_4a36ef55-8008-485d-8ab7-567d9ef25fd8" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedBalancePrincipalAmount_b20eebd6-7e0a-45f6-8c6c-4f8cc6221ca5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedBalancePrincipalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_InvestmentHoldingLineItems_3a64cccb-e906-49fe-995c-17a7bd720899" xlink:to="loc_us-gaap_InvestmentOwnedBalancePrincipalAmount_b20eebd6-7e0a-45f6-8c6c-4f8cc6221ca5" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtCost_05c9ae29-bbdf-4d6a-ac1c-a96282ea2eb7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedAtCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_InvestmentHoldingLineItems_3a64cccb-e906-49fe-995c-17a7bd720899" xlink:to="loc_us-gaap_InvestmentOwnedAtCost_05c9ae29-bbdf-4d6a-ac1c-a96282ea2eb7" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtFairValue_12e0e9a5-8f7a-47bd-8bd6-490cc0f1b059" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_InvestmentHoldingLineItems_3a64cccb-e906-49fe-995c-17a7bd720899" xlink:to="loc_us-gaap_InvestmentOwnedAtFairValue_12e0e9a5-8f7a-47bd-8bd6-490cc0f1b059" xlink:type="arc" order="9"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/FairValueofFinancialInstrumentsScheduleofInvestmentsMeasuredatFairValueonRecurringBasisDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#FairValueofFinancialInstrumentsScheduleofInvestmentsMeasuredatFairValueonRecurringBasisDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/FairValueofFinancialInstrumentsScheduleofInvestmentsMeasuredatFairValueonRecurringBasisDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_56639187-0d50-4311-8399-c5467af383f1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_675bcaf4-25fe-42c7-89df-f58dcf9547b1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_56639187-0d50-4311-8399-c5467af383f1" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_675bcaf4-25fe-42c7-89df-f58dcf9547b1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByAssetClassAxis_0829da9a-a132-49bf-9a34-b98212b77973" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByAssetClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_675bcaf4-25fe-42c7-89df-f58dcf9547b1" xlink:to="loc_us-gaap_FairValueByAssetClassAxis_0829da9a-a132-49bf-9a34-b98212b77973" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_0829da9a-a132-49bf-9a34-b98212b77973_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_0829da9a-a132-49bf-9a34-b98212b77973" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_0829da9a-a132-49bf-9a34-b98212b77973_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_9bde4c3a-8a87-42d4-8f2a-ca68a78ecfa3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_0829da9a-a132-49bf-9a34-b98212b77973" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_9bde4c3a-8a87-42d4-8f2a-ca68a78ecfa3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_EscrowAndOtherInvestmentReceivableMember_3d2e090f-9967-4f2e-bcf1-753e8c1277ec" xlink:href="htgc-20240630.xsd#htgc_EscrowAndOtherInvestmentReceivableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_9bde4c3a-8a87-42d4-8f2a-ca68a78ecfa3" xlink:to="loc_htgc_EscrowAndOtherInvestmentReceivableMember_3d2e090f-9967-4f2e-bcf1-753e8c1277ec" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MoneyMarketFundsMember_c6977a18-528b-47d2-bf16-9e461290aebd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MoneyMarketFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_9bde4c3a-8a87-42d4-8f2a-ca68a78ecfa3" xlink:to="loc_us-gaap_MoneyMarketFundsMember_c6977a18-528b-47d2-bf16-9e461290aebd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_a725c3dd-10a9-4df3-98e9-635043f0123d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByMeasurementFrequencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_675bcaf4-25fe-42c7-89df-f58dcf9547b1" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_a725c3dd-10a9-4df3-98e9-635043f0123d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_a725c3dd-10a9-4df3-98e9-635043f0123d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_a725c3dd-10a9-4df3-98e9-635043f0123d" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_a725c3dd-10a9-4df3-98e9-635043f0123d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_3d62711d-e910-4dea-871e-6d147e8d0101" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_a725c3dd-10a9-4df3-98e9-635043f0123d" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_3d62711d-e910-4dea-871e-6d147e8d0101" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_6798dade-876e-4b37-bf05-29dd184ebaf3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsRecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_3d62711d-e910-4dea-871e-6d147e8d0101" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_6798dade-876e-4b37-bf05-29dd184ebaf3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_540756ee-b410-4d40-b953-511984bd45ce" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_675bcaf4-25fe-42c7-89df-f58dcf9547b1" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_540756ee-b410-4d40-b953-511984bd45ce" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_540756ee-b410-4d40-b953-511984bd45ce_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_540756ee-b410-4d40-b953-511984bd45ce" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_540756ee-b410-4d40-b953-511984bd45ce_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_7d07141d-769a-47f8-883a-0478d2feacaf" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_540756ee-b410-4d40-b953-511984bd45ce" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_7d07141d-769a-47f8-883a-0478d2feacaf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_2af85eeb-9b7c-4d24-8d51-56b068805a81" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_7d07141d-769a-47f8-883a-0478d2feacaf" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_2af85eeb-9b7c-4d24-8d51-56b068805a81" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_642cda3e-0a37-4dec-a686-0282fb07ce75" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_7d07141d-769a-47f8-883a-0478d2feacaf" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_642cda3e-0a37-4dec-a686-0282fb07ce75" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_c7928597-6941-4fe9-b034-dda2583b5f15" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_7d07141d-769a-47f8-883a-0478d2feacaf" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_c7928597-6941-4fe9-b034-dda2583b5f15" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_5400fa0e-9ed6-460f-9ae8-6e21f63a34fd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_675bcaf4-25fe-42c7-89df-f58dcf9547b1" xlink:to="loc_us-gaap_FinancialInstrumentAxis_5400fa0e-9ed6-460f-9ae8-6e21f63a34fd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_5400fa0e-9ed6-460f-9ae8-6e21f63a34fd_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_5400fa0e-9ed6-460f-9ae8-6e21f63a34fd" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_5400fa0e-9ed6-460f-9ae8-6e21f63a34fd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0042aedd-d950-418d-a0b6-66c89b353b1d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_5400fa0e-9ed6-460f-9ae8-6e21f63a34fd" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0042aedd-d950-418d-a0b6-66c89b353b1d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SeniorSecuredDebtMember_fabe46c9-3e9b-41b0-9466-d4e83cdffd23" xlink:href="htgc-20240630.xsd#htgc_SeniorSecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0042aedd-d950-418d-a0b6-66c89b353b1d" xlink:to="loc_htgc_SeniorSecuredDebtMember_fabe46c9-3e9b-41b0-9466-d4e83cdffd23" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnsecuredDebtMember_f50f6edf-21be-4d18-aad7-9b834c995514" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnsecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0042aedd-d950-418d-a0b6-66c89b353b1d" xlink:to="loc_us-gaap_UnsecuredDebtMember_f50f6edf-21be-4d18-aad7-9b834c995514" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockMember_4c620cc3-344b-4f87-a0ad-b1216f95b02d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0042aedd-d950-418d-a0b6-66c89b353b1d" xlink:to="loc_us-gaap_PreferredStockMember_4c620cc3-344b-4f87-a0ad-b1216f95b02d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_d4369032-ac3d-43ed-8a4b-539f1b85d761" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0042aedd-d950-418d-a0b6-66c89b353b1d" xlink:to="loc_us-gaap_CommonStockMember_d4369032-ac3d-43ed-8a4b-539f1b85d761" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantMember_94fd219f-e319-4d3d-bc14-bd5e49e8693a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_WarrantMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0042aedd-d950-418d-a0b6-66c89b353b1d" xlink:to="loc_us-gaap_WarrantMember_94fd219f-e319-4d3d-bc14-bd5e49e8693a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrivateEquityFundsForeignMember_4b7c25c3-2e04-466b-b8a4-4b53c07f3b38" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PrivateEquityFundsForeignMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0042aedd-d950-418d-a0b6-66c89b353b1d" xlink:to="loc_us-gaap_PrivateEquityFundsForeignMember_4b7c25c3-2e04-466b-b8a4-4b53c07f3b38" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_InvestmentsExcludingDerivativeInstrumentsIncludingCashAndCashEquivalentsAndOtherAssetsMember_bb2be2d1-e6c3-49e8-98eb-ffe3a0b3bb2d" xlink:href="htgc-20240630.xsd#htgc_InvestmentsExcludingDerivativeInstrumentsIncludingCashAndCashEquivalentsAndOtherAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0042aedd-d950-418d-a0b6-66c89b353b1d" xlink:to="loc_htgc_InvestmentsExcludingDerivativeInstrumentsIncludingCashAndCashEquivalentsAndOtherAssetsMember_bb2be2d1-e6c3-49e8-98eb-ffe3a0b3bb2d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DerivativeInstrumentMember_1481b0ee-6724-45b2-b760-d8f50a2f4b30" xlink:href="htgc-20240630.xsd#htgc_DerivativeInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0042aedd-d950-418d-a0b6-66c89b353b1d" xlink:to="loc_htgc_DerivativeInstrumentMember_1481b0ee-6724-45b2-b760-d8f50a2f4b30" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_IncludingCashAndCashEquivalentsAndDerivativeInstrumentsMember_c6ed92a4-afb4-4fc2-bcd4-d42650105a17" xlink:href="htgc-20240630.xsd#htgc_IncludingCashAndCashEquivalentsAndDerivativeInstrumentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_0042aedd-d950-418d-a0b6-66c89b353b1d" xlink:to="loc_htgc_IncludingCashAndCashEquivalentsAndDerivativeInstrumentsMember_c6ed92a4-afb4-4fc2-bcd4-d42650105a17" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_f1aacf0a-a648-499f-b3c1-0a70486b22e3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_56639187-0d50-4311-8399-c5467af383f1" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_f1aacf0a-a648-499f-b3c1-0a70486b22e3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsFairValueDisclosure_4a9fbc07-a61c-41ae-9b0d-ad800250067f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherAssetsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_56639187-0d50-4311-8399-c5467af383f1" xlink:to="loc_us-gaap_OtherAssetsFairValueDisclosure_4a9fbc07-a61c-41ae-9b0d-ad800250067f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentsFairValueDisclosure_45521d7e-4b3d-41b1-a354-aab0d7f4735d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_56639187-0d50-4311-8399-c5467af383f1" xlink:to="loc_us-gaap_InvestmentsFairValueDisclosure_45521d7e-4b3d-41b1-a354-aab0d7f4735d" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/FairValueofFinancialInstrumentsSummaryofReconciliationofChangesforAllFinancialAssetsandLiabilitiesMeasuredatFairValueonRecurringBasisDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#FairValueofFinancialInstrumentsSummaryofReconciliationofChangesforAllFinancialAssetsandLiabilitiesMeasuredatFairValueonRecurringBasisDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/FairValueofFinancialInstrumentsSummaryofReconciliationofChangesforAllFinancialAssetsandLiabilitiesMeasuredatFairValueonRecurringBasisDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_29fbb732-309e-4f85-a6f8-c90c85d4aa04" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_3eea6d7c-d97c-4ba5-abfd-7a57e40d3b59" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_29fbb732-309e-4f85-a6f8-c90c85d4aa04" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_3eea6d7c-d97c-4ba5-abfd-7a57e40d3b59" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_3a66b2ad-5a10-48b9-b044-694d7885132d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_3eea6d7c-d97c-4ba5-abfd-7a57e40d3b59" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_3a66b2ad-5a10-48b9-b044-694d7885132d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_3a66b2ad-5a10-48b9-b044-694d7885132d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_3a66b2ad-5a10-48b9-b044-694d7885132d" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_3a66b2ad-5a10-48b9-b044-694d7885132d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_c608aae6-1789-4e2f-b701-396a0bd03524" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_3a66b2ad-5a10-48b9-b044-694d7885132d" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_c608aae6-1789-4e2f-b701-396a0bd03524" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_eb950c6d-c688-468f-bedd-afe01f5d536e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_c608aae6-1789-4e2f-b701-396a0bd03524" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_eb950c6d-c688-468f-bedd-afe01f5d536e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_993eb37a-9c90-4832-85f3-2a8bd6a92ecb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByMeasurementFrequencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_3eea6d7c-d97c-4ba5-abfd-7a57e40d3b59" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_993eb37a-9c90-4832-85f3-2a8bd6a92ecb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_993eb37a-9c90-4832-85f3-2a8bd6a92ecb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_993eb37a-9c90-4832-85f3-2a8bd6a92ecb" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_993eb37a-9c90-4832-85f3-2a8bd6a92ecb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_23db5c2d-d37f-4c4a-a691-706a02bee926" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_993eb37a-9c90-4832-85f3-2a8bd6a92ecb" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_23db5c2d-d37f-4c4a-a691-706a02bee926" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_a89d88be-4f5a-4c1b-bafd-99ce5c3ce8dd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsRecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_23db5c2d-d37f-4c4a-a691-706a02bee926" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_a89d88be-4f5a-4c1b-bafd-99ce5c3ce8dd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_1365ac6c-59e3-4b94-b3b6-da809f3b2812" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_3eea6d7c-d97c-4ba5-abfd-7a57e40d3b59" xlink:to="loc_us-gaap_InvestmentTypeAxis_1365ac6c-59e3-4b94-b3b6-da809f3b2812" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_1365ac6c-59e3-4b94-b3b6-da809f3b2812_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_1365ac6c-59e3-4b94-b3b6-da809f3b2812" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_1365ac6c-59e3-4b94-b3b6-da809f3b2812_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_dddab5b5-62e9-41e5-a103-991ca19ba102" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_1365ac6c-59e3-4b94-b3b6-da809f3b2812" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_dddab5b5-62e9-41e5-a103-991ca19ba102" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SeniorSecuredDebtMember_118c3b21-59c0-4d32-92fb-e9acca580aca" xlink:href="htgc-20240630.xsd#htgc_SeniorSecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_dddab5b5-62e9-41e5-a103-991ca19ba102" xlink:to="loc_htgc_SeniorSecuredDebtMember_118c3b21-59c0-4d32-92fb-e9acca580aca" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnsecuredDebtMember_21dcd990-19b1-4528-9065-dc3daeff699d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnsecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_dddab5b5-62e9-41e5-a103-991ca19ba102" xlink:to="loc_us-gaap_UnsecuredDebtMember_21dcd990-19b1-4528-9065-dc3daeff699d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_EscrowAndOtherInvestmentReceivableMember_788f0441-19f9-4e0f-96e8-3c35c89383b6" xlink:href="htgc-20240630.xsd#htgc_EscrowAndOtherInvestmentReceivableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_dddab5b5-62e9-41e5-a103-991ca19ba102" xlink:to="loc_htgc_EscrowAndOtherInvestmentReceivableMember_788f0441-19f9-4e0f-96e8-3c35c89383b6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_EscrowReceivableMember_74f52e3b-2a70-409c-a9f7-9ee3a94ce319" xlink:href="htgc-20240630.xsd#htgc_EscrowReceivableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_dddab5b5-62e9-41e5-a103-991ca19ba102" xlink:to="loc_htgc_EscrowReceivableMember_74f52e3b-2a70-409c-a9f7-9ee3a94ce319" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_abefa2b2-c498-4a2f-ad16-fc4a4860912d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_3eea6d7c-d97c-4ba5-abfd-7a57e40d3b59" xlink:to="loc_us-gaap_FinancialInstrumentAxis_abefa2b2-c498-4a2f-ad16-fc4a4860912d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_abefa2b2-c498-4a2f-ad16-fc4a4860912d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_abefa2b2-c498-4a2f-ad16-fc4a4860912d" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_abefa2b2-c498-4a2f-ad16-fc4a4860912d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_1814fbd8-839b-4404-910e-a6c5658c489c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_abefa2b2-c498-4a2f-ad16-fc4a4860912d" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_1814fbd8-839b-4404-910e-a6c5658c489c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockMember_1c76fb95-9d5e-4247-b237-ae1c1f27f5c6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_1814fbd8-839b-4404-910e-a6c5658c489c" xlink:to="loc_us-gaap_PreferredStockMember_1c76fb95-9d5e-4247-b237-ae1c1f27f5c6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_4e78e9c3-e3e2-4fab-8905-9241a88cf167" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_1814fbd8-839b-4404-910e-a6c5658c489c" xlink:to="loc_us-gaap_CommonStockMember_4e78e9c3-e3e2-4fab-8905-9241a88cf167" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantMember_1b6ca2ec-75a0-4c35-a7aa-62483172c165" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_WarrantMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_1814fbd8-839b-4404-910e-a6c5658c489c" xlink:to="loc_us-gaap_WarrantMember_1b6ca2ec-75a0-4c35-a7aa-62483172c165" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_7eb4e38c-c160-42f9-a5d3-7ea636a40fa5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_29fbb732-309e-4f85-a6f8-c90c85d4aa04" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_7eb4e38c-c160-42f9-a5d3-7ea636a40fa5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_a6eba012-3bc2-4fc6-940b-2c47aed7d32d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_7eb4e38c-c160-42f9-a5d3-7ea636a40fa5" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_a6eba012-3bc2-4fc6-940b-2c47aed7d32d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1_7048917d-c4e8-4e42-8b6b-61791e1fd55b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_7eb4e38c-c160-42f9-a5d3-7ea636a40fa5" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1_7048917d-c4e8-4e42-8b6b-61791e1fd55b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPeriodIncreaseDecrease_5e9bd312-638d-4a9f-8879-136a8188672f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPeriodIncreaseDecrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_7eb4e38c-c160-42f9-a5d3-7ea636a40fa5" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPeriodIncreaseDecrease_5e9bd312-638d-4a9f-8879-136a8188672f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases_01180657-f89a-42fd-a858-6c460308fe5b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_7eb4e38c-c160-42f9-a5d3-7ea636a40fa5" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases_01180657-f89a-42fd-a858-6c460308fe5b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales_3d99c4a1-9eb7-40f1-b6d5-9b1e55210db5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_7eb4e38c-c160-42f9-a5d3-7ea636a40fa5" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales_3d99c4a1-9eb7-40f1-b6d5-9b1e55210db5" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements_be3e6e1b-a0e1-4af0-be5a-601e0d30447c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_7eb4e38c-c160-42f9-a5d3-7ea636a40fa5" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements_be3e6e1b-a0e1-4af0-be5a-601e0d30447c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3_eb9bbba2-ce5f-4090-b2a6-e3d482d2e869" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_7eb4e38c-c160-42f9-a5d3-7ea636a40fa5" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersIntoLevel3_eb9bbba2-ce5f-4090-b2a6-e3d482d2e869" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3_745abb48-a9ed-4b0e-9598-daf081ffb920" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_7eb4e38c-c160-42f9-a5d3-7ea636a40fa5" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3_745abb48-a9ed-4b0e-9598-daf081ffb920" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_e283698d-4e6c-45f7-bb18-bef2a6de46b4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/FairValueofFinancialInstrumentsScheduleofEquityInvestmentsDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#FairValueofFinancialInstrumentsScheduleofEquityInvestmentsDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/FairValueofFinancialInstrumentsScheduleofEquityInvestmentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_c29c2b3c-594c-41e2-9bad-3d824dde22c9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_9ee28b49-2ccc-4ccb-b2e1-a707bf258bec" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_c29c2b3c-594c-41e2-9bad-3d824dde22c9" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_9ee28b49-2ccc-4ccb-b2e1-a707bf258bec" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_2722ed77-ae85-46a6-bd1f-49a2cc92a812" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_9ee28b49-2ccc-4ccb-b2e1-a707bf258bec" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_2722ed77-ae85-46a6-bd1f-49a2cc92a812" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_2722ed77-ae85-46a6-bd1f-49a2cc92a812_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_2722ed77-ae85-46a6-bd1f-49a2cc92a812" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_2722ed77-ae85-46a6-bd1f-49a2cc92a812_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0c3bb59b-65d2-46a1-b6a3-3b64bf345f04" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_2722ed77-ae85-46a6-bd1f-49a2cc92a812" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0c3bb59b-65d2-46a1-b6a3-3b64bf345f04" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_b45e4472-bb8e-451f-bead-390af153402a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0c3bb59b-65d2-46a1-b6a3-3b64bf345f04" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_b45e4472-bb8e-451f-bead-390af153402a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_52d0fd0c-00bd-4764-9b2f-6f45773d11a2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_9ee28b49-2ccc-4ccb-b2e1-a707bf258bec" xlink:to="loc_us-gaap_FinancialInstrumentAxis_52d0fd0c-00bd-4764-9b2f-6f45773d11a2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_52d0fd0c-00bd-4764-9b2f-6f45773d11a2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_52d0fd0c-00bd-4764-9b2f-6f45773d11a2" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_52d0fd0c-00bd-4764-9b2f-6f45773d11a2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_033cf87d-328c-44e6-a845-f2377aa90f37" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_52d0fd0c-00bd-4764-9b2f-6f45773d11a2" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_033cf87d-328c-44e6-a845-f2377aa90f37" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DebtInvestmentsMember_2b23c59b-4db9-4c85-9db7-849ed79798b9" xlink:href="htgc-20240630.xsd#htgc_DebtInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_033cf87d-328c-44e6-a845-f2377aa90f37" xlink:to="loc_htgc_DebtInvestmentsMember_2b23c59b-4db9-4c85-9db7-849ed79798b9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_PreferredStockInvestmentMember_d9ec91fe-db89-463e-97d1-fbbba4ea17e1" xlink:href="htgc-20240630.xsd#htgc_PreferredStockInvestmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_033cf87d-328c-44e6-a845-f2377aa90f37" xlink:to="loc_htgc_PreferredStockInvestmentMember_d9ec91fe-db89-463e-97d1-fbbba4ea17e1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CommonStockInvestmentMember_fb8d722f-cc33-4392-8a4d-d4b58874b330" xlink:href="htgc-20240630.xsd#htgc_CommonStockInvestmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_033cf87d-328c-44e6-a845-f2377aa90f37" xlink:to="loc_htgc_CommonStockInvestmentMember_fb8d722f-cc33-4392-8a4d-d4b58874b330" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_WarrantInvestmentMember_d14b3bf1-a595-4ae0-89bb-a2447194ead2" xlink:href="htgc-20240630.xsd#htgc_WarrantInvestmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_033cf87d-328c-44e6-a845-f2377aa90f37" xlink:to="loc_htgc_WarrantInvestmentMember_d14b3bf1-a595-4ae0-89bb-a2447194ead2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossOnInvestments_d7982595-976a-44a1-8d00-ed8612403184" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnrealizedGainLossOnInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_c29c2b3c-594c-41e2-9bad-3d824dde22c9" xlink:to="loc_us-gaap_UnrealizedGainLossOnInvestments_d7982595-976a-44a1-8d00-ed8612403184" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/FairValueofFinancialInstrumentsScheduleofQuantitativeInformationofFairValueMeasurementsDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#FairValueofFinancialInstrumentsScheduleofQuantitativeInformationofFairValueMeasurementsDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/FairValueofFinancialInstrumentsScheduleofQuantitativeInformationofFairValueMeasurementsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_266c371b-bcb5-421b-9412-1ffe17c98566" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_58026e6b-5699-4b8f-b835-07be0ad130b7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_266c371b-bcb5-421b-9412-1ffe17c98566" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_58026e6b-5699-4b8f-b835-07be0ad130b7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_b3de796f-a621-4096-839a-d5c99eff444d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_58026e6b-5699-4b8f-b835-07be0ad130b7" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_b3de796f-a621-4096-839a-d5c99eff444d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_b3de796f-a621-4096-839a-d5c99eff444d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_b3de796f-a621-4096-839a-d5c99eff444d" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_b3de796f-a621-4096-839a-d5c99eff444d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_78be2a26-8caf-44df-b5f9-2a985ebf31de" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_b3de796f-a621-4096-839a-d5c99eff444d" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_78be2a26-8caf-44df-b5f9-2a985ebf31de" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_718519ac-3be9-44c2-b28f-8ef186c544b0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_78be2a26-8caf-44df-b5f9-2a985ebf31de" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_718519ac-3be9-44c2-b28f-8ef186c544b0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueAxis_8c782823-cb37-424d-8e98-518eba0634fd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ValuationTechniqueAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_58026e6b-5699-4b8f-b835-07be0ad130b7" xlink:to="loc_us-gaap_ValuationTechniqueAxis_8c782823-cb37-424d-8e98-518eba0634fd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueDomain_8c782823-cb37-424d-8e98-518eba0634fd_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ValuationTechniqueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ValuationTechniqueAxis_8c782823-cb37-424d-8e98-518eba0634fd" xlink:to="loc_us-gaap_ValuationTechniqueDomain_8c782823-cb37-424d-8e98-518eba0634fd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueDomain_9c51c64a-51e8-4a43-be45-050bac34a8b4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ValuationTechniqueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ValuationTechniqueAxis_8c782823-cb37-424d-8e98-518eba0634fd" xlink:to="loc_us-gaap_ValuationTechniqueDomain_9c51c64a-51e8-4a43-be45-050bac34a8b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketApproachValuationTechniqueMember_f021bd6a-b420-4ff1-ad92-b79c9866a34c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MarketApproachValuationTechniqueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationTechniqueDomain_9c51c64a-51e8-4a43-be45-050bac34a8b4" xlink:to="loc_us-gaap_MarketApproachValuationTechniqueMember_f021bd6a-b420-4ff1-ad92-b79c9866a34c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ValuationTechniqueLiquidationMember_258ab3ff-c4af-483d-86fc-26f858c7f591" xlink:href="htgc-20240630.xsd#htgc_ValuationTechniqueLiquidationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationTechniqueDomain_9c51c64a-51e8-4a43-be45-050bac34a8b4" xlink:to="loc_htgc_ValuationTechniqueLiquidationMember_258ab3ff-c4af-483d-86fc-26f858c7f591" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeApproachValuationTechniqueMember_e87e60f5-d4cb-48f0-b7a3-d4fc9b372d56" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeApproachValuationTechniqueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationTechniqueDomain_9c51c64a-51e8-4a43-be45-050bac34a8b4" xlink:to="loc_us-gaap_IncomeApproachValuationTechniqueMember_e87e60f5-d4cb-48f0-b7a3-d4fc9b372d56" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueOptionPricingModelMember_705a4c4c-9297-4ea0-a378-a952333f84ff" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ValuationTechniqueOptionPricingModelMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationTechniqueDomain_9c51c64a-51e8-4a43-be45-050bac34a8b4" xlink:to="loc_us-gaap_ValuationTechniqueOptionPricingModelMember_705a4c4c-9297-4ea0-a378-a952333f84ff" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueDiscountedCashFlowMember_0a4cc5f3-dce7-481b-8264-5ac4eb4affc3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ValuationTechniqueDiscountedCashFlowMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationTechniqueDomain_9c51c64a-51e8-4a43-be45-050bac34a8b4" xlink:to="loc_us-gaap_ValuationTechniqueDiscountedCashFlowMember_0a4cc5f3-dce7-481b-8264-5ac4eb4affc3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ValuationTechniqueOtherMember_d680d33e-074b-4fe5-b1e9-bfe425a6ae8a" xlink:href="htgc-20240630.xsd#htgc_ValuationTechniqueOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationTechniqueDomain_9c51c64a-51e8-4a43-be45-050bac34a8b4" xlink:to="loc_htgc_ValuationTechniqueOtherMember_d680d33e-074b-4fe5-b1e9-bfe425a6ae8a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostApproachValuationTechniqueMember_75b97961-9925-49c9-b3ae-eb2bf58c46b6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CostApproachValuationTechniqueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationTechniqueDomain_9c51c64a-51e8-4a43-be45-050bac34a8b4" xlink:to="loc_us-gaap_CostApproachValuationTechniqueMember_75b97961-9925-49c9-b3ae-eb2bf58c46b6" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DebtInvestmentsImminentPayoffsMember_01f507ad-0693-4885-8216-4743c897491a" xlink:href="htgc-20240630.xsd#htgc_DebtInvestmentsImminentPayoffsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationTechniqueDomain_9c51c64a-51e8-4a43-be45-050bac34a8b4" xlink:to="loc_htgc_DebtInvestmentsImminentPayoffsMember_01f507ad-0693-4885-8216-4743c897491a" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DebtMaturingWithinOneYearMember_2ba184b2-7ff7-41c8-a7b0-5aa65fe2a875" xlink:href="htgc-20240630.xsd#htgc_DebtMaturingWithinOneYearMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationTechniqueDomain_9c51c64a-51e8-4a43-be45-050bac34a8b4" xlink:to="loc_htgc_DebtMaturingWithinOneYearMember_2ba184b2-7ff7-41c8-a7b0-5aa65fe2a875" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_4861cb05-6e03-4325-849f-a0acd56f81e9" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_58026e6b-5699-4b8f-b835-07be0ad130b7" xlink:to="loc_srt_RangeAxis_4861cb05-6e03-4325-849f-a0acd56f81e9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_4861cb05-6e03-4325-849f-a0acd56f81e9_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_4861cb05-6e03-4325-849f-a0acd56f81e9" xlink:to="loc_srt_RangeMember_4861cb05-6e03-4325-849f-a0acd56f81e9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_7692c8fa-eeb0-4b92-8750-e21434171b6c" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_4861cb05-6e03-4325-849f-a0acd56f81e9" xlink:to="loc_srt_RangeMember_7692c8fa-eeb0-4b92-8750-e21434171b6c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_ed9f1ad2-0e07-4a32-94fb-a46179ca9a27" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_7692c8fa-eeb0-4b92-8750-e21434171b6c" xlink:to="loc_srt_MinimumMember_ed9f1ad2-0e07-4a32-94fb-a46179ca9a27" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_56fae8af-d320-44f6-b688-4b97e8ae03a0" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_7692c8fa-eeb0-4b92-8750-e21434171b6c" xlink:to="loc_srt_MaximumMember_56fae8af-d320-44f6-b688-4b97e8ae03a0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_WeightedAverageMember_217a1026-c7e5-498b-9ae4-9f4a7f092f0a" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_WeightedAverageMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_7692c8fa-eeb0-4b92-8750-e21434171b6c" xlink:to="loc_srt_WeightedAverageMember_217a1026-c7e5-498b-9ae4-9f4a7f092f0a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeAxis_a490c0ef-86fe-40cb-9c2e-e8489674063e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_58026e6b-5699-4b8f-b835-07be0ad130b7" xlink:to="loc_us-gaap_MeasurementInputTypeAxis_a490c0ef-86fe-40cb-9c2e-e8489674063e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_a490c0ef-86fe-40cb-9c2e-e8489674063e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_a490c0ef-86fe-40cb-9c2e-e8489674063e" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_a490c0ef-86fe-40cb-9c2e-e8489674063e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_13f0b8be-5910-406a-93c8-6e24391d8ce8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_a490c0ef-86fe-40cb-9c2e-e8489674063e" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_13f0b8be-5910-406a-93c8-6e24391d8ce8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MeasurementInputHypotheticalMarketYieldMember_f3bfb12d-c9e9-4dea-b069-e8b99dd69004" xlink:href="htgc-20240630.xsd#htgc_MeasurementInputHypotheticalMarketYieldMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_13f0b8be-5910-406a-93c8-6e24391d8ce8" xlink:to="loc_htgc_MeasurementInputHypotheticalMarketYieldMember_f3bfb12d-c9e9-4dea-b069-e8b99dd69004" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MeasurementInputPremiumDiscountNettingMember_0cdbefbc-4c3f-472e-9794-77305c6eb9a2" xlink:href="htgc-20240630.xsd#htgc_MeasurementInputPremiumDiscountNettingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_13f0b8be-5910-406a-93c8-6e24391d8ce8" xlink:to="loc_htgc_MeasurementInputPremiumDiscountNettingMember_0cdbefbc-4c3f-472e-9794-77305c6eb9a2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MeasurementInputsProbabilityWeightingOfAlternativeOutcomesMember_809dcae6-b11d-43e9-befb-e0c5e573a65c" xlink:href="htgc-20240630.xsd#htgc_MeasurementInputsProbabilityWeightingOfAlternativeOutcomesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_13f0b8be-5910-406a-93c8-6e24391d8ce8" xlink:to="loc_htgc_MeasurementInputsProbabilityWeightingOfAlternativeOutcomesMember_809dcae6-b11d-43e9-befb-e0c5e573a65c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputDiscountRateMember_cd317287-e6a4-4a08-a7ca-74d474b37c9e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputDiscountRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_13f0b8be-5910-406a-93c8-6e24391d8ce8" xlink:to="loc_us-gaap_MeasurementInputDiscountRateMember_cd317287-e6a4-4a08-a7ca-74d474b37c9e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputEbitdaMultipleMember_964b07a6-875a-4e82-956f-41269ca346f5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputEbitdaMultipleMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_13f0b8be-5910-406a-93c8-6e24391d8ce8" xlink:to="loc_us-gaap_MeasurementInputEbitdaMultipleMember_964b07a6-875a-4e82-956f-41269ca346f5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputRevenueMultipleMember_0d9ac1c5-dacf-4cca-8e45-75ba93ef9043" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputRevenueMultipleMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_13f0b8be-5910-406a-93c8-6e24391d8ce8" xlink:to="loc_us-gaap_MeasurementInputRevenueMultipleMember_0d9ac1c5-dacf-4cca-8e45-75ba93ef9043" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MeasurementInputTangibleBookValueMultipleMember_7b092310-4c8e-45d1-8004-1011f4ed5054" xlink:href="htgc-20240630.xsd#htgc_MeasurementInputTangibleBookValueMultipleMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_13f0b8be-5910-406a-93c8-6e24391d8ce8" xlink:to="loc_htgc_MeasurementInputTangibleBookValueMultipleMember_7b092310-4c8e-45d1-8004-1011f4ed5054" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputDiscountForLackOfMarketabilityMember_4cef4ff8-2ed7-41d7-9b37-18c987cd35c3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputDiscountForLackOfMarketabilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_13f0b8be-5910-406a-93c8-6e24391d8ce8" xlink:to="loc_us-gaap_MeasurementInputDiscountForLackOfMarketabilityMember_4cef4ff8-2ed7-41d7-9b37-18c987cd35c3" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MeasurementInputMarketEquityAdjustmentMember_133252df-d4a1-496f-b03b-a7d820d7b6c2" xlink:href="htgc-20240630.xsd#htgc_MeasurementInputMarketEquityAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_13f0b8be-5910-406a-93c8-6e24391d8ce8" xlink:to="loc_htgc_MeasurementInputMarketEquityAdjustmentMember_133252df-d4a1-496f-b03b-a7d820d7b6c2" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesByIndustryAxis_1aaf1582-89b1-4393-aee3-c03ae32fdddd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquitySecuritiesByIndustryAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_58026e6b-5699-4b8f-b835-07be0ad130b7" xlink:to="loc_us-gaap_EquitySecuritiesByIndustryAxis_1aaf1582-89b1-4393-aee3-c03ae32fdddd" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesIndustryMember_1aaf1582-89b1-4393-aee3-c03ae32fdddd_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquitySecuritiesIndustryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_EquitySecuritiesByIndustryAxis_1aaf1582-89b1-4393-aee3-c03ae32fdddd" xlink:to="loc_us-gaap_EquitySecuritiesIndustryMember_1aaf1582-89b1-4393-aee3-c03ae32fdddd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesIndustryMember_bf31fbf4-2fad-43a6-a132-2d98538d81b7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquitySecuritiesIndustryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_EquitySecuritiesByIndustryAxis_1aaf1582-89b1-4393-aee3-c03ae32fdddd" xlink:to="loc_us-gaap_EquitySecuritiesIndustryMember_bf31fbf4-2fad-43a6-a132-2d98538d81b7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_PharmaceuticalsMember_77b9dd10-2a44-4c42-98df-ba4e08929c12" xlink:href="htgc-20240630.xsd#htgc_PharmaceuticalsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesIndustryMember_bf31fbf4-2fad-43a6-a132-2d98538d81b7" xlink:to="loc_htgc_PharmaceuticalsMember_77b9dd10-2a44-4c42-98df-ba4e08929c12" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TechnologyMember_110954c7-da8d-443f-ab1b-5d84c14ee672" xlink:href="htgc-20240630.xsd#htgc_TechnologyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesIndustryMember_bf31fbf4-2fad-43a6-a132-2d98538d81b7" xlink:to="loc_htgc_TechnologyMember_110954c7-da8d-443f-ab1b-5d84c14ee672" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SustainableAndRenewableTechnologyMember_cc558612-bc09-470d-ad4c-c94eae1ffa5f" xlink:href="htgc-20240630.xsd#htgc_SustainableAndRenewableTechnologyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesIndustryMember_bf31fbf4-2fad-43a6-a132-2d98538d81b7" xlink:to="loc_htgc_SustainableAndRenewableTechnologyMember_cc558612-bc09-470d-ad4c-c94eae1ffa5f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MedicalDevicesMember_8ef9d9a2-3071-4438-9cdf-764298cf5c7c" xlink:href="htgc-20240630.xsd#htgc_MedicalDevicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesIndustryMember_bf31fbf4-2fad-43a6-a132-2d98538d81b7" xlink:to="loc_htgc_MedicalDevicesMember_8ef9d9a2-3071-4438-9cdf-764298cf5c7c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_LowerMiddleMarketMember_2f564bdd-930d-4dbf-a668-bfd9f9b8be5e" xlink:href="htgc-20240630.xsd#htgc_LowerMiddleMarketMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesIndustryMember_bf31fbf4-2fad-43a6-a132-2d98538d81b7" xlink:to="loc_htgc_LowerMiddleMarketMember_2f564bdd-930d-4dbf-a668-bfd9f9b8be5e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_OtherInvestmentReceivableMember_96e4e0de-b0ca-4206-94df-866cbb15aeaf" xlink:href="htgc-20240630.xsd#htgc_OtherInvestmentReceivableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesIndustryMember_bf31fbf4-2fad-43a6-a132-2d98538d81b7" xlink:to="loc_htgc_OtherInvestmentReceivableMember_96e4e0de-b0ca-4206-94df-866cbb15aeaf" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_54c6bd27-2237-4997-9237-0efd2cf59c1c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_58026e6b-5699-4b8f-b835-07be0ad130b7" xlink:to="loc_us-gaap_FinancialInstrumentAxis_54c6bd27-2237-4997-9237-0efd2cf59c1c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_54c6bd27-2237-4997-9237-0efd2cf59c1c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_54c6bd27-2237-4997-9237-0efd2cf59c1c" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_54c6bd27-2237-4997-9237-0efd2cf59c1c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_3df71b83-fa4d-478d-adc0-bb790b065e6c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_54c6bd27-2237-4997-9237-0efd2cf59c1c" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_3df71b83-fa4d-478d-adc0-bb790b065e6c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DebtInvestmentsMember_9c031559-f02a-4456-9351-00e237fa29a7" xlink:href="htgc-20240630.xsd#htgc_DebtInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_3df71b83-fa4d-478d-adc0-bb790b065e6c" xlink:to="loc_htgc_DebtInvestmentsMember_9c031559-f02a-4456-9351-00e237fa29a7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesMember_fc483826-c8e5-495b-92bd-af7109a0c57f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquitySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_3df71b83-fa4d-478d-adc0-bb790b065e6c" xlink:to="loc_us-gaap_EquitySecuritiesMember_fc483826-c8e5-495b-92bd-af7109a0c57f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantMember_05ac60f2-c08e-46b1-962f-42aa278c09e6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_WarrantMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_3df71b83-fa4d-478d-adc0-bb790b065e6c" xlink:to="loc_us-gaap_WarrantMember_05ac60f2-c08e-46b1-962f-42aa278c09e6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_EquityAndWarrantInvestmentsMember_d6389121-e8e3-43cd-aedf-46ddad31fcdf" xlink:href="htgc-20240630.xsd#htgc_EquityAndWarrantInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_3df71b83-fa4d-478d-adc0-bb790b065e6c" xlink:to="loc_htgc_EquityAndWarrantInvestmentsMember_d6389121-e8e3-43cd-aedf-46ddad31fcdf" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_OtherInvestmentReceivablesMember_49f8a9e2-791b-4781-a0f2-32af65df09cc" xlink:href="htgc-20240630.xsd#htgc_OtherInvestmentReceivablesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_3df71b83-fa4d-478d-adc0-bb790b065e6c" xlink:to="loc_htgc_OtherInvestmentReceivablesMember_49f8a9e2-791b-4781-a0f2-32af65df09cc" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DebtInvestmentsAndOtherInvestmentReceivablesMember_a09205eb-a997-4f7e-a1f5-8b2c8d1d943e" xlink:href="htgc-20240630.xsd#htgc_DebtInvestmentsAndOtherInvestmentReceivablesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_3df71b83-fa4d-478d-adc0-bb790b065e6c" xlink:to="loc_htgc_DebtInvestmentsAndOtherInvestmentReceivablesMember_a09205eb-a997-4f7e-a1f5-8b2c8d1d943e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentsFairValueDisclosure_4a935ffe-4be2-41c1-92d9-775d939c66b0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_266c371b-bcb5-421b-9412-1ffe17c98566" xlink:to="loc_us-gaap_InvestmentsFairValueDisclosure_4a935ffe-4be2-41c1-92d9-775d939c66b0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyInvestmentOwnedFairValueMeasurementInput_223a0d50-726b-4922-9c5c-6b2a05f5cd49" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentCompanyInvestmentOwnedFairValueMeasurementInput"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_266c371b-bcb5-421b-9412-1ffe17c98566" xlink:to="loc_us-gaap_InvestmentCompanyInvestmentOwnedFairValueMeasurementInput_223a0d50-726b-4922-9c5c-6b2a05f5cd49" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/FairValueofFinancialInstrumentsNarrativeDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#FairValueofFinancialInstrumentsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/FairValueofFinancialInstrumentsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_8d9d68e2-21eb-4a5c-8e16-c4d78ee254d0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_6c56b6bd-dc04-4189-aa31-d640e0396d76" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_8d9d68e2-21eb-4a5c-8e16-c4d78ee254d0" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_6c56b6bd-dc04-4189-aa31-d640e0396d76" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_b73c2f68-15d4-418c-904d-2c69979af4a2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_6c56b6bd-dc04-4189-aa31-d640e0396d76" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_b73c2f68-15d4-418c-904d-2c69979af4a2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_b73c2f68-15d4-418c-904d-2c69979af4a2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_b73c2f68-15d4-418c-904d-2c69979af4a2" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_b73c2f68-15d4-418c-904d-2c69979af4a2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_ca0ca6b7-566f-4b0a-b8b4-453a8038bf91" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_b73c2f68-15d4-418c-904d-2c69979af4a2" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_ca0ca6b7-566f-4b0a-b8b4-453a8038bf91" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TwoThousandThirtyThreeNotesMember_a5ca9f64-e028-4e32-9915-700c13760558" xlink:href="htgc-20240630.xsd#htgc_TwoThousandThirtyThreeNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_ca0ca6b7-566f-4b0a-b8b4-453a8038bf91" xlink:to="loc_htgc_TwoThousandThirtyThreeNotesMember_a5ca9f64-e028-4e32-9915-700c13760558" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TwoThousandThirtyOneAssetBackedNotesMember_8493b9fa-9ebe-4938-b3f4-747ca2fc4666" xlink:href="htgc-20240630.xsd#htgc_TwoThousandThirtyOneAssetBackedNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_ca0ca6b7-566f-4b0a-b8b4-453a8038bf91" xlink:to="loc_htgc_TwoThousandThirtyOneAssetBackedNotesMember_8493b9fa-9ebe-4938-b3f4-747ca2fc4666" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_aa38f036-3990-4d4f-b796-d7c138bdef11" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_6c56b6bd-dc04-4189-aa31-d640e0396d76" xlink:to="loc_us-gaap_FinancialInstrumentAxis_aa38f036-3990-4d4f-b796-d7c138bdef11" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_aa38f036-3990-4d4f-b796-d7c138bdef11_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_aa38f036-3990-4d4f-b796-d7c138bdef11" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_aa38f036-3990-4d4f-b796-d7c138bdef11_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_8d29544b-2e6c-44bc-8e1e-df22d6727115" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_aa38f036-3990-4d4f-b796-d7c138bdef11" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_8d29544b-2e6c-44bc-8e1e-df22d6727115" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_UnderwritingMember_9acc14e2-424d-4000-94e1-447c6c205fbb" xlink:href="htgc-20240630.xsd#htgc_UnderwritingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_8d29544b-2e6c-44bc-8e1e-df22d6727115" xlink:to="loc_htgc_UnderwritingMember_9acc14e2-424d-4000-94e1-447c6c205fbb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CurrentPricePerParValue_8c1c1cb8-9348-4f50-8957-131082c716ae" xlink:href="htgc-20240630.xsd#htgc_CurrentPricePerParValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_8d9d68e2-21eb-4a5c-8e16-c4d78ee254d0" xlink:to="loc_htgc_CurrentPricePerParValue_8c1c1cb8-9348-4f50-8957-131082c716ae" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/FairValueofFinancialInstrumentsScheduleofFairValueHierarchyOfOutstandingBorrowingsDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#FairValueofFinancialInstrumentsScheduleofFairValueHierarchyOfOutstandingBorrowingsDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/FairValueofFinancialInstrumentsScheduleofFairValueHierarchyOfOutstandingBorrowingsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_22bac7f7-b25c-4cad-9d05-a7380bf3a8e0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByBalanceSheetGroupingTable_15ca0976-6932-4f70-961e-87accf1fc8fd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByBalanceSheetGroupingTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_22bac7f7-b25c-4cad-9d05-a7380bf3a8e0" xlink:to="loc_us-gaap_FairValueByBalanceSheetGroupingTable_15ca0976-6932-4f70-961e-87accf1fc8fd" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementBasisAxis_b627d2c6-c1bd-488a-a9b6-f187ccacf3da" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByMeasurementBasisAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_15ca0976-6932-4f70-961e-87accf1fc8fd" xlink:to="loc_us-gaap_FairValueByMeasurementBasisAxis_b627d2c6-c1bd-488a-a9b6-f187ccacf3da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_b627d2c6-c1bd-488a-a9b6-f187ccacf3da_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_b627d2c6-c1bd-488a-a9b6-f187ccacf3da" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_b627d2c6-c1bd-488a-a9b6-f187ccacf3da_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueDisclosureItemAmountsDomain_967526ed-dcf3-4b40-ae2a-499931a52a73" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueDisclosureItemAmountsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_b627d2c6-c1bd-488a-a9b6-f187ccacf3da" xlink:to="loc_us-gaap_FairValueDisclosureItemAmountsDomain_967526ed-dcf3-4b40-ae2a-499931a52a73" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_cbd3a5cf-beaf-4035-9dbb-98d7f0e6cc74" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_967526ed-dcf3-4b40-ae2a-499931a52a73" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_cbd3a5cf-beaf-4035-9dbb-98d7f0e6cc74" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_863219f4-a224-4c0d-8e2d-335cddb0a67d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CarryingReportedAmountFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_cbd3a5cf-beaf-4035-9dbb-98d7f0e6cc74" xlink:to="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_863219f4-a224-4c0d-8e2d-335cddb0a67d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_ed867ac0-504b-4b60-b4ee-01279479d6de" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EstimateOfFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_cbd3a5cf-beaf-4035-9dbb-98d7f0e6cc74" xlink:to="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_ed867ac0-504b-4b60-b4ee-01279479d6de" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_d314cba7-7a32-4bfc-b406-7d8b392220c8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_15ca0976-6932-4f70-961e-87accf1fc8fd" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_d314cba7-7a32-4bfc-b406-7d8b392220c8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_d314cba7-7a32-4bfc-b406-7d8b392220c8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_d314cba7-7a32-4bfc-b406-7d8b392220c8" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_d314cba7-7a32-4bfc-b406-7d8b392220c8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_435602c7-277e-429f-b4c7-76030908c403" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_d314cba7-7a32-4bfc-b406-7d8b392220c8" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_435602c7-277e-429f-b4c7-76030908c403" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesMember_b5cb3b5a-d0c2-4c76-9859-8c31385a2100" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_435602c7-277e-429f-b4c7-76030908c403" xlink:to="loc_htgc_SBADebenturesMember_b5cb3b5a-d0c2-4c76-9859-8c31385a2100" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JulyTwoThousandTwentyFourNotesMember_be54c324-4896-4c90-a0ea-4198746c1cd3" xlink:href="htgc-20240630.xsd#htgc_JulyTwoThousandTwentyFourNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_435602c7-277e-429f-b4c7-76030908c403" xlink:to="loc_htgc_JulyTwoThousandTwentyFourNotesMember_be54c324-4896-4c90-a0ea-4198746c1cd3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_FebruaryTwoThousandTwentyFiveNotesMember_57f65a25-a5e5-411a-b787-55df381eb969" xlink:href="htgc-20240630.xsd#htgc_FebruaryTwoThousandTwentyFiveNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_435602c7-277e-429f-b4c7-76030908c403" xlink:to="loc_htgc_FebruaryTwoThousandTwentyFiveNotesMember_57f65a25-a5e5-411a-b787-55df381eb969" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JuneTwoThousandTwentyFiveNotesMember_967ee4b1-10b1-4156-a756-555cbd364a39" xlink:href="htgc-20240630.xsd#htgc_JuneTwoThousandTwentyFiveNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_435602c7-277e-429f-b4c7-76030908c403" xlink:to="loc_htgc_JuneTwoThousandTwentyFiveNotesMember_967ee4b1-10b1-4156-a756-555cbd364a39" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JuneTwoThousandTwentyFiveThreeYearNotesMember_7bb9080a-a855-416c-832a-c0cab62cc25e" xlink:href="htgc-20240630.xsd#htgc_JuneTwoThousandTwentyFiveThreeYearNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_435602c7-277e-429f-b4c7-76030908c403" xlink:to="loc_htgc_JuneTwoThousandTwentyFiveThreeYearNotesMember_7bb9080a-a855-416c-832a-c0cab62cc25e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MarchTwoThousandTwentySixANotesMember_f61335be-defa-4bd1-8a8e-0f204532d3b7" xlink:href="htgc-20240630.xsd#htgc_MarchTwoThousandTwentySixANotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_435602c7-277e-429f-b4c7-76030908c403" xlink:to="loc_htgc_MarchTwoThousandTwentySixANotesMember_f61335be-defa-4bd1-8a8e-0f204532d3b7" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MarchTwoThousandTwentySixBNotesMember_2414fcce-0f7e-4880-81f0-c79a7e760a62" xlink:href="htgc-20240630.xsd#htgc_MarchTwoThousandTwentySixBNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_435602c7-277e-429f-b4c7-76030908c403" xlink:to="loc_htgc_MarchTwoThousandTwentySixBNotesMember_2414fcce-0f7e-4880-81f0-c79a7e760a62" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SeptemberTwoThousandTwentySixNotesMember_d6e4450a-3c63-4a6d-8b78-03a985586b9b" xlink:href="htgc-20240630.xsd#htgc_SeptemberTwoThousandTwentySixNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_435602c7-277e-429f-b4c7-76030908c403" xlink:to="loc_htgc_SeptemberTwoThousandTwentySixNotesMember_d6e4450a-3c63-4a6d-8b78-03a985586b9b" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JanuaryTwoThousandTwentySevenNotesMember_68119a33-cc9a-4ff4-94e6-6570cf0fc369" xlink:href="htgc-20240630.xsd#htgc_JanuaryTwoThousandTwentySevenNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_435602c7-277e-429f-b4c7-76030908c403" xlink:to="loc_htgc_JanuaryTwoThousandTwentySevenNotesMember_68119a33-cc9a-4ff4-94e6-6570cf0fc369" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TwoThousandThirtyOneAssetBackedNotesMember_8909c36f-ca3b-4deb-b7bf-e97d2d5103a8" xlink:href="htgc-20240630.xsd#htgc_TwoThousandThirtyOneAssetBackedNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_435602c7-277e-429f-b4c7-76030908c403" xlink:to="loc_htgc_TwoThousandThirtyOneAssetBackedNotesMember_8909c36f-ca3b-4deb-b7bf-e97d2d5103a8" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TwoThousandThirtyThreeNotesMember_5dd92fe1-581d-4938-bcb2-97d162da8096" xlink:href="htgc-20240630.xsd#htgc_TwoThousandThirtyThreeNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_435602c7-277e-429f-b4c7-76030908c403" xlink:to="loc_htgc_TwoThousandThirtyThreeNotesMember_5dd92fe1-581d-4938-bcb2-97d162da8096" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MUFGBankFacilityMember_f5036b1a-b575-4bd3-bdf7-849434d4b5d8" xlink:href="htgc-20240630.xsd#htgc_MUFGBankFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_435602c7-277e-429f-b4c7-76030908c403" xlink:to="loc_htgc_MUFGBankFacilityMember_f5036b1a-b575-4bd3-bdf7-849434d4b5d8" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SMBCFacilityMember_cfd5085b-0c24-4084-9b28-04925d23ae2b" xlink:href="htgc-20240630.xsd#htgc_SMBCFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_435602c7-277e-429f-b4c7-76030908c403" xlink:to="loc_htgc_SMBCFacilityMember_cfd5085b-0c24-4084-9b28-04925d23ae2b" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_708afa79-c368-4002-8501-774c68b272ac" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueByBalanceSheetGroupingTable_15ca0976-6932-4f70-961e-87accf1fc8fd" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_708afa79-c368-4002-8501-774c68b272ac" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_708afa79-c368-4002-8501-774c68b272ac_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_708afa79-c368-4002-8501-774c68b272ac" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_708afa79-c368-4002-8501-774c68b272ac_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_59135ea4-d4be-409f-b2ec-e3b416b86a83" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_708afa79-c368-4002-8501-774c68b272ac" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_59135ea4-d4be-409f-b2ec-e3b416b86a83" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_55395ccd-5a7f-42fc-8e9d-67ac21449c38" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_59135ea4-d4be-409f-b2ec-e3b416b86a83" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_55395ccd-5a7f-42fc-8e9d-67ac21449c38" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_49712e91-97d4-4521-9eaf-b0be865c2c49" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_59135ea4-d4be-409f-b2ec-e3b416b86a83" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_49712e91-97d4-4521-9eaf-b0be865c2c49" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_14c340ea-3f83-4fdb-a105-ef9cbcf8707d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_22bac7f7-b25c-4cad-9d05-a7380bf3a8e0" xlink:to="loc_us-gaap_LongTermDebt_14c340ea-3f83-4fdb-a105-ef9cbcf8707d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtFairValue_60fcf380-4d98-4438-ac6b-55e17326d06e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueBalanceSheetGroupingFinancialStatementCaptionsLineItems_22bac7f7-b25c-4cad-9d05-a7380bf3a8e0" xlink:to="loc_us-gaap_LongTermDebtFairValue_60fcf380-4d98-4438-ac6b-55e17326d06e" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/InvestmentsScheduleofRealizedGainsandLossesandChangesinUnrealizedAppreciationandDepreciationonControlandAffiliateinvestmentsDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#InvestmentsScheduleofRealizedGainsandLossesandChangesinUnrealizedAppreciationandDepreciationonControlandAffiliateinvestmentsDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/InvestmentsScheduleofRealizedGainsandLossesandChangesinUnrealizedAppreciationandDepreciationonControlandAffiliateinvestmentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentsLineItems_66d2fed2-5679-41c1-81fb-324d494f7927" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfInvestmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentsTable_5ec38983-4f96-45f4-87b4-f7269d75ba30" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfInvestmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_66d2fed2-5679-41c1-81fb-324d494f7927" xlink:to="loc_us-gaap_ScheduleOfInvestmentsTable_5ec38983-4f96-45f4-87b4-f7269d75ba30" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationAxis_25cbc170-1aa4-4328-b971-a154a57749dc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentIssuerAffiliationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentsTable_5ec38983-4f96-45f4-87b4-f7269d75ba30" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationAxis_25cbc170-1aa4-4328-b971-a154a57749dc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_25cbc170-1aa4-4328-b971-a154a57749dc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_25cbc170-1aa4-4328-b971-a154a57749dc" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_25cbc170-1aa4-4328-b971-a154a57749dc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_d0f03539-c902-4f86-96a5-ac2c7564e58e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_25cbc170-1aa4-4328-b971-a154a57749dc" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_d0f03539-c902-4f86-96a5-ac2c7564e58e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentAffiliatedIssuerControlledMember_474bc491-f9a3-4ce7-8b23-a4be829c94dc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentAffiliatedIssuerControlledMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationDomain_d0f03539-c902-4f86-96a5-ac2c7564e58e" xlink:to="loc_us-gaap_InvestmentAffiliatedIssuerControlledMember_474bc491-f9a3-4ce7-8b23-a4be829c94dc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_c869a042-d188-4c5d-9f71-204f680f014e" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentsTable_5ec38983-4f96-45f4-87b4-f7269d75ba30" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_c869a042-d188-4c5d-9f71-204f680f014e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_c869a042-d188-4c5d-9f71-204f680f014e_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_c869a042-d188-4c5d-9f71-204f680f014e" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_c869a042-d188-4c5d-9f71-204f680f014e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_14f61fc9-0390-4b77-9f85-415e7d0a65a2" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_c869a042-d188-4c5d-9f71-204f680f014e" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_14f61fc9-0390-4b77-9f85-415e7d0a65a2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CoronadoAestheticsLLCMember_6a3a3381-a6fb-4383-b75b-c8e3429e11f0" xlink:href="htgc-20240630.xsd#htgc_CoronadoAestheticsLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_14f61fc9-0390-4b77-9f85-415e7d0a65a2" xlink:to="loc_htgc_CoronadoAestheticsLLCMember_6a3a3381-a6fb-4383-b75b-c8e3429e11f0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_GibraltarAcquisitionLLCMember_8a8eff17-39c8-4344-882b-18805fa736ff" xlink:href="htgc-20240630.xsd#htgc_GibraltarAcquisitionLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_14f61fc9-0390-4b77-9f85-415e7d0a65a2" xlink:to="loc_htgc_GibraltarAcquisitionLLCMember_8a8eff17-39c8-4344-882b-18805fa736ff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_HerculesAdviserLLCMember_3d6e6dd6-a83d-497f-a35c-0e9a1188567d" xlink:href="htgc-20240630.xsd#htgc_HerculesAdviserLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_14f61fc9-0390-4b77-9f85-415e7d0a65a2" xlink:to="loc_htgc_HerculesAdviserLLCMember_3d6e6dd6-a83d-497f-a35c-0e9a1188567d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TecturaCorporationMember_827a388c-c66e-4336-89b1-80caae2ce53c" xlink:href="htgc-20240630.xsd#htgc_TecturaCorporationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_14f61fc9-0390-4b77-9f85-415e7d0a65a2" xlink:to="loc_htgc_TecturaCorporationMember_827a388c-c66e-4336-89b1-80caae2ce53c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtFairValue_dcc8b504-d0a3-4a51-8ec3-925568712e02" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_66d2fed2-5679-41c1-81fb-324d494f7927" xlink:to="loc_us-gaap_InvestmentOwnedAtFairValue_dcc8b504-d0a3-4a51-8ec3-925568712e02" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndDividendIncomeOperating_944ee8cf-7a93-49bf-a9ac-33667000d06a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestAndDividendIncomeOperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_66d2fed2-5679-41c1-81fb-324d494f7927" xlink:to="loc_us-gaap_InterestAndDividendIncomeOperating_944ee8cf-7a93-49bf-a9ac-33667000d06a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FeeIncome_28fbebb3-dbaf-4c43-8029-fb369062ddf7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FeeIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_66d2fed2-5679-41c1-81fb-324d494f7927" xlink:to="loc_us-gaap_FeeIncome_28fbebb3-dbaf-4c43-8029-fb369062ddf7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossOnInvestments_dc1817ec-a506-430c-906a-f74d67af678d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnrealizedGainLossOnInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_66d2fed2-5679-41c1-81fb-324d494f7927" xlink:to="loc_us-gaap_UnrealizedGainLossOnInvestments_dc1817ec-a506-430c-906a-f74d67af678d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealizedInvestmentGainsLosses_6f0317c1-98d9-40c4-9706-e5696bfd2cac" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RealizedInvestmentGainsLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_66d2fed2-5679-41c1-81fb-324d494f7927" xlink:to="loc_us-gaap_RealizedInvestmentGainsLosses_6f0317c1-98d9-40c4-9706-e5696bfd2cac" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/InvestmentsScheduleofFairValuePortfolioofInvestmentsbyAssetClassDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#InvestmentsScheduleofFairValuePortfolioofInvestmentsbyAssetClassDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/InvestmentsScheduleofFairValuePortfolioofInvestmentsbyAssetClassDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentsLineItems_86961140-646e-4c12-a569-8c73fb02a203" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfInvestmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentsTable_3d11e580-5d1c-4a8c-bde0-8b72a5ea5f0e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfInvestmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_86961140-646e-4c12-a569-8c73fb02a203" xlink:to="loc_us-gaap_ScheduleOfInvestmentsTable_3d11e580-5d1c-4a8c-bde0-8b72a5ea5f0e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_00849c0c-427a-48e6-97da-9810c38bb82e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentsTable_3d11e580-5d1c-4a8c-bde0-8b72a5ea5f0e" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_00849c0c-427a-48e6-97da-9810c38bb82e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_00849c0c-427a-48e6-97da-9810c38bb82e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_00849c0c-427a-48e6-97da-9810c38bb82e" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_00849c0c-427a-48e6-97da-9810c38bb82e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_a3bff689-fcda-4de5-ab78-cc1d4b40eed3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_00849c0c-427a-48e6-97da-9810c38bb82e" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_a3bff689-fcda-4de5-ab78-cc1d4b40eed3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_InvestmentTypeConcentrationRiskMember_3606a1b7-2541-4638-be86-edc9d110d281" xlink:href="htgc-20240630.xsd#htgc_InvestmentTypeConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_a3bff689-fcda-4de5-ab78-cc1d4b40eed3" xlink:to="loc_htgc_InvestmentTypeConcentrationRiskMember_3606a1b7-2541-4638-be86-edc9d110d281" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_3d774126-c585-4d91-958b-1a80a834ae4f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentsTable_3d11e580-5d1c-4a8c-bde0-8b72a5ea5f0e" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_3d774126-c585-4d91-958b-1a80a834ae4f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_3d774126-c585-4d91-958b-1a80a834ae4f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_3d774126-c585-4d91-958b-1a80a834ae4f" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_3d774126-c585-4d91-958b-1a80a834ae4f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_c167d277-f936-4e89-9b6c-5fc1d4ecf9d6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_3d774126-c585-4d91-958b-1a80a834ae4f" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_c167d277-f936-4e89-9b6c-5fc1d4ecf9d6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TotalInvestmentsBenchmarkMember_8866748e-ce9d-487b-bc49-4b76d84ac01a" xlink:href="htgc-20240630.xsd#htgc_TotalInvestmentsBenchmarkMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_c167d277-f936-4e89-9b6c-5fc1d4ecf9d6" xlink:to="loc_htgc_TotalInvestmentsBenchmarkMember_8866748e-ce9d-487b-bc49-4b76d84ac01a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_ec06633f-8f70-45a9-af86-9bfbeaed3da7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentsTable_3d11e580-5d1c-4a8c-bde0-8b72a5ea5f0e" xlink:to="loc_us-gaap_InvestmentTypeAxis_ec06633f-8f70-45a9-af86-9bfbeaed3da7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_ec06633f-8f70-45a9-af86-9bfbeaed3da7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_ec06633f-8f70-45a9-af86-9bfbeaed3da7" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_ec06633f-8f70-45a9-af86-9bfbeaed3da7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_1f06e133-6546-4914-9faa-d8bfe7c04de8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_ec06633f-8f70-45a9-af86-9bfbeaed3da7" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_1f06e133-6546-4914-9faa-d8bfe7c04de8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SeniorSecuredDebtMember_5044b4b3-482e-4346-b5e9-b8609fd05560" xlink:href="htgc-20240630.xsd#htgc_SeniorSecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_1f06e133-6546-4914-9faa-d8bfe7c04de8" xlink:to="loc_htgc_SeniorSecuredDebtMember_5044b4b3-482e-4346-b5e9-b8609fd05560" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnsecuredDebtMember_7eeead99-3e37-4d01-809e-04314dbb7898" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnsecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_1f06e133-6546-4914-9faa-d8bfe7c04de8" xlink:to="loc_us-gaap_UnsecuredDebtMember_7eeead99-3e37-4d01-809e-04314dbb7898" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockMember_c3fe9cdc-93a3-4652-9481-082ad6996646" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_1f06e133-6546-4914-9faa-d8bfe7c04de8" xlink:to="loc_us-gaap_PreferredStockMember_c3fe9cdc-93a3-4652-9481-082ad6996646" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_8fc1d5a6-2fe1-4110-9500-79acfe3c1dbc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_1f06e133-6546-4914-9faa-d8bfe7c04de8" xlink:to="loc_us-gaap_CommonStockMember_8fc1d5a6-2fe1-4110-9500-79acfe3c1dbc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_WarrantInvestmentMember_8a0340aa-91e6-4412-ba62-5cfbbc8c109d" xlink:href="htgc-20240630.xsd#htgc_WarrantInvestmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_1f06e133-6546-4914-9faa-d8bfe7c04de8" xlink:to="loc_htgc_WarrantInvestmentMember_8a0340aa-91e6-4412-ba62-5cfbbc8c109d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_InvestmentFundsAndVehiclesMember_333e8d04-b66e-49bf-9c89-50ac789cfc25" xlink:href="htgc-20240630.xsd#htgc_InvestmentFundsAndVehiclesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_1f06e133-6546-4914-9faa-d8bfe7c04de8" xlink:to="loc_htgc_InvestmentFundsAndVehiclesMember_333e8d04-b66e-49bf-9c89-50ac789cfc25" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtFairValue_eaf2ae7d-9f03-4d90-9787-6371e4082041" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_86961140-646e-4c12-a569-8c73fb02a203" xlink:to="loc_us-gaap_InvestmentOwnedAtFairValue_eaf2ae7d-9f03-4d90-9787-6371e4082041" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_cf1d084d-19e5-4b60-9e3d-b83e07c3d50a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_86961140-646e-4c12-a569-8c73fb02a203" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_cf1d084d-19e5-4b60-9e3d-b83e07c3d50a" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/InvestmentsScheduleofFairValuePortfolioofInvestmentsbyGeographicLocationDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#InvestmentsScheduleofFairValuePortfolioofInvestmentsbyGeographicLocationDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/InvestmentsScheduleofFairValuePortfolioofInvestmentsbyGeographicLocationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentsLineItems_d4480659-f5bd-4049-86ac-796be055f952" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfInvestmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentsTable_37ba42d5-6f86-4e00-91b7-85b3fdb0d66c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfInvestmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_d4480659-f5bd-4049-86ac-796be055f952" xlink:to="loc_us-gaap_ScheduleOfInvestmentsTable_37ba42d5-6f86-4e00-91b7-85b3fdb0d66c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_b26b00c8-a8c7-4b85-a1b5-ded291fdb0e0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentsTable_37ba42d5-6f86-4e00-91b7-85b3fdb0d66c" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_b26b00c8-a8c7-4b85-a1b5-ded291fdb0e0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_b26b00c8-a8c7-4b85-a1b5-ded291fdb0e0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_b26b00c8-a8c7-4b85-a1b5-ded291fdb0e0" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_b26b00c8-a8c7-4b85-a1b5-ded291fdb0e0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_9ef1217a-687e-4b7b-847d-955965349307" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_b26b00c8-a8c7-4b85-a1b5-ded291fdb0e0" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_9ef1217a-687e-4b7b-847d-955965349307" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeographicConcentrationRiskMember_dcd10eea-4cfe-4feb-a805-9051dd7469c3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GeographicConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_9ef1217a-687e-4b7b-847d-955965349307" xlink:to="loc_us-gaap_GeographicConcentrationRiskMember_dcd10eea-4cfe-4feb-a805-9051dd7469c3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_439a0ba7-73c7-4490-8db9-eebfc4dccf05" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentsTable_37ba42d5-6f86-4e00-91b7-85b3fdb0d66c" xlink:to="loc_srt_StatementGeographicalAxis_439a0ba7-73c7-4490-8db9-eebfc4dccf05" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_439a0ba7-73c7-4490-8db9-eebfc4dccf05_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_439a0ba7-73c7-4490-8db9-eebfc4dccf05" xlink:to="loc_srt_SegmentGeographicalDomain_439a0ba7-73c7-4490-8db9-eebfc4dccf05_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_5814d954-3a0a-4a6c-8333-e95af1bac8d6" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_439a0ba7-73c7-4490-8db9-eebfc4dccf05" xlink:to="loc_srt_SegmentGeographicalDomain_5814d954-3a0a-4a6c-8333-e95af1bac8d6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_075c01a4-73b0-43da-964d-d8d93e7c670c" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_5814d954-3a0a-4a6c-8333-e95af1bac8d6" xlink:to="loc_country_US_075c01a4-73b0-43da-964d-d8d93e7c670c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_GB_9dfd0d19-3ac7-4b36-8783-f85ef101325d" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_GB"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_5814d954-3a0a-4a6c-8333-e95af1bac8d6" xlink:to="loc_country_GB_9dfd0d19-3ac7-4b36-8783-f85ef101325d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_NL_6344ca3d-1ceb-42c0-9af6-53899bc5b8cd" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_NL"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_5814d954-3a0a-4a6c-8333-e95af1bac8d6" xlink:to="loc_country_NL_6344ca3d-1ceb-42c0-9af6-53899bc5b8cd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_IL_72eed8d6-b4b6-4f73-a54f-43a15317662a" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_IL"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_5814d954-3a0a-4a6c-8333-e95af1bac8d6" xlink:to="loc_country_IL_72eed8d6-b4b6-4f73-a54f-43a15317662a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_CA_144329a8-7c26-40aa-812c-4e7fb9715d5d" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_CA"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_5814d954-3a0a-4a6c-8333-e95af1bac8d6" xlink:to="loc_country_CA_144329a8-7c26-40aa-812c-4e7fb9715d5d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_IE_0e8f31dc-5ccb-4773-aeec-8ac66d56f62a" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_IE"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_5814d954-3a0a-4a6c-8333-e95af1bac8d6" xlink:to="loc_country_IE_0e8f31dc-5ccb-4773-aeec-8ac66d56f62a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_DK_89c6658f-fd7b-42c7-8f3f-12725af996ad" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_DK"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_5814d954-3a0a-4a6c-8333-e95af1bac8d6" xlink:to="loc_country_DK_89c6658f-fd7b-42c7-8f3f-12725af996ad" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_SG_d0ec7b41-e07d-4cfc-abd8-3663cda5e4d8" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_SG"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_5814d954-3a0a-4a6c-8333-e95af1bac8d6" xlink:to="loc_country_SG_d0ec7b41-e07d-4cfc-abd8-3663cda5e4d8" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_DE_acfeda9d-7162-4712-8102-73915afc601b" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_DE"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_5814d954-3a0a-4a6c-8333-e95af1bac8d6" xlink:to="loc_country_DE_acfeda9d-7162-4712-8102-73915afc601b" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_OtherCountriesMember_eb57e3e3-e3eb-4406-8f1b-4e2de257ae1b" xlink:href="htgc-20240630.xsd#htgc_OtherCountriesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_5814d954-3a0a-4a6c-8333-e95af1bac8d6" xlink:to="loc_htgc_OtherCountriesMember_eb57e3e3-e3eb-4406-8f1b-4e2de257ae1b" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_a4c2f9a6-f82d-41bb-a9e8-4400ebb75017" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentsTable_37ba42d5-6f86-4e00-91b7-85b3fdb0d66c" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_a4c2f9a6-f82d-41bb-a9e8-4400ebb75017" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_a4c2f9a6-f82d-41bb-a9e8-4400ebb75017_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_a4c2f9a6-f82d-41bb-a9e8-4400ebb75017" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_a4c2f9a6-f82d-41bb-a9e8-4400ebb75017_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_88a84333-30fc-4c59-ac4d-a8f9871b850b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_a4c2f9a6-f82d-41bb-a9e8-4400ebb75017" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_88a84333-30fc-4c59-ac4d-a8f9871b850b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TotalInvestmentsBenchmarkGeographicalMember_9abbe567-1a9f-4d94-95c2-c6245b152e69" xlink:href="htgc-20240630.xsd#htgc_TotalInvestmentsBenchmarkGeographicalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_88a84333-30fc-4c59-ac4d-a8f9871b850b" xlink:to="loc_htgc_TotalInvestmentsBenchmarkGeographicalMember_9abbe567-1a9f-4d94-95c2-c6245b152e69" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtFairValue_0998dd45-72a1-4459-abe0-6cde65f0ed9b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_d4480659-f5bd-4049-86ac-796be055f952" xlink:to="loc_us-gaap_InvestmentOwnedAtFairValue_0998dd45-72a1-4459-abe0-6cde65f0ed9b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_16b0880c-74eb-460c-ac4a-95a53fb6f2c5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_d4480659-f5bd-4049-86ac-796be055f952" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_16b0880c-74eb-460c-ac4a-95a53fb6f2c5" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/InvestmentsScheduleofFairValuePortfoliobyIndustrySectorDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#InvestmentsScheduleofFairValuePortfoliobyIndustrySectorDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/InvestmentsScheduleofFairValuePortfoliobyIndustrySectorDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentsLineItems_771fb7c5-2eec-4977-9d0f-5b408514b317" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfInvestmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentsTable_efb33feb-ccab-47ea-8e8a-da0b92fafd2e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfInvestmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_771fb7c5-2eec-4977-9d0f-5b408514b317" xlink:to="loc_us-gaap_ScheduleOfInvestmentsTable_efb33feb-ccab-47ea-8e8a-da0b92fafd2e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_ed90c076-ff93-4aae-8e99-d4dba5fad11d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentsTable_efb33feb-ccab-47ea-8e8a-da0b92fafd2e" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_ed90c076-ff93-4aae-8e99-d4dba5fad11d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_ed90c076-ff93-4aae-8e99-d4dba5fad11d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_ed90c076-ff93-4aae-8e99-d4dba5fad11d" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_ed90c076-ff93-4aae-8e99-d4dba5fad11d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_6a34926c-5574-4f0c-b97c-f58174bc4892" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_ed90c076-ff93-4aae-8e99-d4dba5fad11d" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_6a34926c-5574-4f0c-b97c-f58174bc4892" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_IndustrySectorConcentrationRiskMember_6df4ede4-e1a1-4b13-be10-d392606136b2" xlink:href="htgc-20240630.xsd#htgc_IndustrySectorConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_6a34926c-5574-4f0c-b97c-f58174bc4892" xlink:to="loc_htgc_IndustrySectorConcentrationRiskMember_6df4ede4-e1a1-4b13-be10-d392606136b2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_d4a43b33-a1f3-4d7a-96e9-405005c135d0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentsTable_efb33feb-ccab-47ea-8e8a-da0b92fafd2e" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_d4a43b33-a1f3-4d7a-96e9-405005c135d0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_d4a43b33-a1f3-4d7a-96e9-405005c135d0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_d4a43b33-a1f3-4d7a-96e9-405005c135d0" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_d4a43b33-a1f3-4d7a-96e9-405005c135d0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_19d2a704-f22f-4748-b8cf-6e83a1f45b4a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_d4a43b33-a1f3-4d7a-96e9-405005c135d0" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_19d2a704-f22f-4748-b8cf-6e83a1f45b4a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_IndustrySubSectorInvestmentsBenchmarkMember_2fac9f0c-26d8-4028-8c23-a677a3240f2d" xlink:href="htgc-20240630.xsd#htgc_IndustrySubSectorInvestmentsBenchmarkMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_19d2a704-f22f-4748-b8cf-6e83a1f45b4a" xlink:to="loc_htgc_IndustrySubSectorInvestmentsBenchmarkMember_2fac9f0c-26d8-4028-8c23-a677a3240f2d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesByIndustryAxis_ab857940-86d2-49cc-94ea-bffc36d2505d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquitySecuritiesByIndustryAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentsTable_efb33feb-ccab-47ea-8e8a-da0b92fafd2e" xlink:to="loc_us-gaap_EquitySecuritiesByIndustryAxis_ab857940-86d2-49cc-94ea-bffc36d2505d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesIndustryMember_ab857940-86d2-49cc-94ea-bffc36d2505d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquitySecuritiesIndustryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_EquitySecuritiesByIndustryAxis_ab857940-86d2-49cc-94ea-bffc36d2505d" xlink:to="loc_us-gaap_EquitySecuritiesIndustryMember_ab857940-86d2-49cc-94ea-bffc36d2505d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesIndustryMember_37998883-4d0d-42e5-b426-24b7f9ff18ad" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquitySecuritiesIndustryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_EquitySecuritiesByIndustryAxis_ab857940-86d2-49cc-94ea-bffc36d2505d" xlink:to="loc_us-gaap_EquitySecuritiesIndustryMember_37998883-4d0d-42e5-b426-24b7f9ff18ad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TotalIndustrySectorsMember_63521367-44ae-4934-bae1-44184a313db7" xlink:href="htgc-20240630.xsd#htgc_TotalIndustrySectorsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesIndustryMember_37998883-4d0d-42e5-b426-24b7f9ff18ad" xlink:to="loc_htgc_TotalIndustrySectorsMember_63521367-44ae-4934-bae1-44184a313db7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DrugDiscoveryAndDevelopmentMember_f43337c3-e165-4da8-967d-a4ee3f895420" xlink:href="htgc-20240630.xsd#htgc_DrugDiscoveryAndDevelopmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_TotalIndustrySectorsMember_63521367-44ae-4934-bae1-44184a313db7" xlink:to="loc_htgc_DrugDiscoveryAndDevelopmentMember_f43337c3-e165-4da8-967d-a4ee3f895420" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SoftwareMember_b958ec1f-6e92-40b4-87f3-c1b102b23479" xlink:href="htgc-20240630.xsd#htgc_SoftwareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_TotalIndustrySectorsMember_63521367-44ae-4934-bae1-44184a313db7" xlink:to="loc_htgc_SoftwareMember_b958ec1f-6e92-40b4-87f3-c1b102b23479" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ConsumerAndBusinessServicesMember_06baf92a-8be3-4d46-b1f3-20a64a65bb3e" xlink:href="htgc-20240630.xsd#htgc_ConsumerAndBusinessServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_TotalIndustrySectorsMember_63521367-44ae-4934-bae1-44184a313db7" xlink:to="loc_htgc_ConsumerAndBusinessServicesMember_06baf92a-8be3-4d46-b1f3-20a64a65bb3e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_HealthcareServicesOtherMember_56014644-23bc-4c07-bab0-29f040713d66" xlink:href="htgc-20240630.xsd#htgc_HealthcareServicesOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_TotalIndustrySectorsMember_63521367-44ae-4934-bae1-44184a313db7" xlink:to="loc_htgc_HealthcareServicesOtherMember_56014644-23bc-4c07-bab0-29f040713d66" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_InformationServicesMember_2e5bb114-5bed-47a7-8137-24c789195328" xlink:href="htgc-20240630.xsd#htgc_InformationServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_TotalIndustrySectorsMember_63521367-44ae-4934-bae1-44184a313db7" xlink:to="loc_htgc_InformationServicesMember_2e5bb114-5bed-47a7-8137-24c789195328" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DiversifiedFinancialServicesMember_97bde759-d7ef-422d-a01d-ff7b857b7f5b" xlink:href="htgc-20240630.xsd#htgc_DiversifiedFinancialServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_TotalIndustrySectorsMember_63521367-44ae-4934-bae1-44184a313db7" xlink:to="loc_htgc_DiversifiedFinancialServicesMember_97bde759-d7ef-422d-a01d-ff7b857b7f5b" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ElectronicsComputerHardwareMember_bb30f95f-3c12-4ff7-81e8-693ebb8c367b" xlink:href="htgc-20240630.xsd#htgc_ElectronicsComputerHardwareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_TotalIndustrySectorsMember_63521367-44ae-4934-bae1-44184a313db7" xlink:to="loc_htgc_ElectronicsComputerHardwareMember_bb30f95f-3c12-4ff7-81e8-693ebb8c367b" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MedicalDevicesAndEquipmentMember_3452809c-aad7-4a8f-b775-d5cef6fddad9" xlink:href="htgc-20240630.xsd#htgc_MedicalDevicesAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_TotalIndustrySectorsMember_63521367-44ae-4934-bae1-44184a313db7" xlink:to="loc_htgc_MedicalDevicesAndEquipmentMember_3452809c-aad7-4a8f-b775-d5cef6fddad9" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SpaceTechnologiesMember_5a41ef0a-2387-43d7-baad-87c1e9ad84bd" xlink:href="htgc-20240630.xsd#htgc_SpaceTechnologiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_TotalIndustrySectorsMember_63521367-44ae-4934-bae1-44184a313db7" xlink:to="loc_htgc_SpaceTechnologiesMember_5a41ef0a-2387-43d7-baad-87c1e9ad84bd" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_BiotechnologyToolsMember_52e376e6-675a-41e3-953b-f07af6472892" xlink:href="htgc-20240630.xsd#htgc_BiotechnologyToolsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_TotalIndustrySectorsMember_63521367-44ae-4934-bae1-44184a313db7" xlink:to="loc_htgc_BiotechnologyToolsMember_52e376e6-675a-41e3-953b-f07af6472892" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CommunicationsAndNetworkingMember_e4366c48-6191-4d52-948e-5165704fff29" xlink:href="htgc-20240630.xsd#htgc_CommunicationsAndNetworkingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_TotalIndustrySectorsMember_63521367-44ae-4934-bae1-44184a313db7" xlink:to="loc_htgc_CommunicationsAndNetworkingMember_e4366c48-6191-4d52-948e-5165704fff29" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SustainableAndRenewableTechnologyMember_089c7f61-1e19-4ec5-8dbd-85eb2d836068" xlink:href="htgc-20240630.xsd#htgc_SustainableAndRenewableTechnologyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_TotalIndustrySectorsMember_63521367-44ae-4934-bae1-44184a313db7" xlink:to="loc_htgc_SustainableAndRenewableTechnologyMember_089c7f61-1e19-4ec5-8dbd-85eb2d836068" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MediaContentInfoMember_65eab513-923a-411e-9fa2-da269c2a953a" xlink:href="htgc-20240630.xsd#htgc_MediaContentInfoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_TotalIndustrySectorsMember_63521367-44ae-4934-bae1-44184a313db7" xlink:to="loc_htgc_MediaContentInfoMember_65eab513-923a-411e-9fa2-da269c2a953a" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ManufacturingTechnologyMember_269b1525-0aff-49b2-b5fd-446b339fa877" xlink:href="htgc-20240630.xsd#htgc_ManufacturingTechnologyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_TotalIndustrySectorsMember_63521367-44ae-4934-bae1-44184a313db7" xlink:to="loc_htgc_ManufacturingTechnologyMember_269b1525-0aff-49b2-b5fd-446b339fa877" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ConsumerAndBusinessProductsMember_1932a848-20bf-4384-b3c8-53815d3ecb11" xlink:href="htgc-20240630.xsd#htgc_ConsumerAndBusinessProductsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_TotalIndustrySectorsMember_63521367-44ae-4934-bae1-44184a313db7" xlink:to="loc_htgc_ConsumerAndBusinessProductsMember_1932a848-20bf-4384-b3c8-53815d3ecb11" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SemiconductorsMember_4f5a5bee-326b-4bdb-a361-28ef42c819e4" xlink:href="htgc-20240630.xsd#htgc_SemiconductorsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_TotalIndustrySectorsMember_63521367-44ae-4934-bae1-44184a313db7" xlink:to="loc_htgc_SemiconductorsMember_4f5a5bee-326b-4bdb-a361-28ef42c819e4" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SurgicalDevicesMember_d92dac48-79a9-45af-a7d1-acd60ebd996f" xlink:href="htgc-20240630.xsd#htgc_SurgicalDevicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_TotalIndustrySectorsMember_63521367-44ae-4934-bae1-44184a313db7" xlink:to="loc_htgc_SurgicalDevicesMember_d92dac48-79a9-45af-a7d1-acd60ebd996f" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DrugDeliveryMember_9747906a-f9e1-42d6-a3ef-a883bf94c120" xlink:href="htgc-20240630.xsd#htgc_DrugDeliveryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_TotalIndustrySectorsMember_63521367-44ae-4934-bae1-44184a313db7" xlink:to="loc_htgc_DrugDeliveryMember_9747906a-f9e1-42d6-a3ef-a883bf94c120" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtFairValue_485f7d46-6f59-47f3-b1fc-33d5475d645f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_771fb7c5-2eec-4977-9d0f-5b408514b317" xlink:to="loc_us-gaap_InvestmentOwnedAtFairValue_485f7d46-6f59-47f3-b1fc-33d5475d645f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_109c732a-3c12-4ad7-825b-f1ab8b7fbe94" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_771fb7c5-2eec-4977-9d0f-5b408514b317" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_109c732a-3c12-4ad7-825b-f1ab8b7fbe94" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/InvestmentsNarrativeDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#InvestmentsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/InvestmentsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentsLineItems_a117c5ad-1a94-4e5e-898b-c10e0d5557a6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfInvestmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentsTable_6b1ff826-44af-47ed-9026-709d9902678a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfInvestmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_a117c5ad-1a94-4e5e-898b-c10e0d5557a6" xlink:to="loc_us-gaap_ScheduleOfInvestmentsTable_6b1ff826-44af-47ed-9026-709d9902678a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_9cc36cfe-272a-4248-9e42-2ac90eaa5027" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentsTable_6b1ff826-44af-47ed-9026-709d9902678a" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_9cc36cfe-272a-4248-9e42-2ac90eaa5027" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_9cc36cfe-272a-4248-9e42-2ac90eaa5027_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_9cc36cfe-272a-4248-9e42-2ac90eaa5027" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_9cc36cfe-272a-4248-9e42-2ac90eaa5027_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_671222d8-90ba-4b28-8505-959f97f89daf" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_9cc36cfe-272a-4248-9e42-2ac90eaa5027" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_671222d8-90ba-4b28-8505-959f97f89daf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditConcentrationRiskMember_57b70f89-c9d4-40d7-93f0-5c347e4d6fdf" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CreditConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_671222d8-90ba-4b28-8505-959f97f89daf" xlink:to="loc_us-gaap_CreditConcentrationRiskMember_57b70f89-c9d4-40d7-93f0-5c347e4d6fdf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TopTenInvestmentPercentOfFairValue_85da1eea-0da2-438c-9923-f3039775efeb" xlink:href="htgc-20240630.xsd#htgc_TopTenInvestmentPercentOfFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_a117c5ad-1a94-4e5e-898b-c10e0d5557a6" xlink:to="loc_htgc_TopTenInvestmentPercentOfFairValue_85da1eea-0da2-438c-9923-f3039775efeb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CountPortfolioCompaniesGreaterThanFivePercent_adc1e259-bd12-41a4-8c13-58fcaaccd428" xlink:href="htgc-20240630.xsd#htgc_CountPortfolioCompaniesGreaterThanFivePercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_a117c5ad-1a94-4e5e-898b-c10e0d5557a6" xlink:to="loc_htgc_CountPortfolioCompaniesGreaterThanFivePercent_adc1e259-bd12-41a4-8c13-58fcaaccd428" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CountGreaterFivePercentFairValueEquity_2ca5937c-9784-48f0-98cb-855358d84ab9" xlink:href="htgc-20240630.xsd#htgc_CountGreaterFivePercentFairValueEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_a117c5ad-1a94-4e5e-898b-c10e0d5557a6" xlink:to="loc_htgc_CountGreaterFivePercentFairValueEquity_2ca5937c-9784-48f0-98cb-855358d84ab9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_PercentGreaterFivePercentFairValueEquity_7fa44b16-b6e3-4452-8524-4f0002cf4221" xlink:href="htgc-20240630.xsd#htgc_PercentGreaterFivePercentFairValueEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_a117c5ad-1a94-4e5e-898b-c10e0d5557a6" xlink:to="loc_htgc_PercentGreaterFivePercentFairValueEquity_7fa44b16-b6e3-4452-8524-4f0002cf4221" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/InvestmentsScheduleofInvestmentCollateralDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#InvestmentsScheduleofInvestmentCollateralDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/InvestmentsScheduleofInvestmentCollateralDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentsLineItems_66772bec-7a20-4df6-9e08-a552f6a2d702" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfInvestmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentsTable_95542843-bb24-4aca-a264-6b4e37119fd5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfInvestmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_66772bec-7a20-4df6-9e08-a552f6a2d702" xlink:to="loc_us-gaap_ScheduleOfInvestmentsTable_95542843-bb24-4aca-a264-6b4e37119fd5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_d311d90f-311b-420f-9425-e2acaa6fff24" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentsTable_95542843-bb24-4aca-a264-6b4e37119fd5" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_d311d90f-311b-420f-9425-e2acaa6fff24" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_d311d90f-311b-420f-9425-e2acaa6fff24_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_d311d90f-311b-420f-9425-e2acaa6fff24" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_d311d90f-311b-420f-9425-e2acaa6fff24_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_a62792b6-8cb2-47b4-a415-607fd7752853" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_d311d90f-311b-420f-9425-e2acaa6fff24" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_a62792b6-8cb2-47b4-a415-607fd7752853" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TotalDebtInvestmentsBenchmarkMember_fe8af160-a0d9-4d2a-b0d3-6cfd90cef655" xlink:href="htgc-20240630.xsd#htgc_TotalDebtInvestmentsBenchmarkMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_a62792b6-8cb2-47b4-a415-607fd7752853" xlink:to="loc_htgc_TotalDebtInvestmentsBenchmarkMember_fe8af160-a0d9-4d2a-b0d3-6cfd90cef655" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralAxis_a1662a07-6dae-4ba3-87cd-b33989d957b7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CollateralAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentsTable_95542843-bb24-4aca-a264-6b4e37119fd5" xlink:to="loc_us-gaap_CollateralAxis_a1662a07-6dae-4ba3-87cd-b33989d957b7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralDomain_a1662a07-6dae-4ba3-87cd-b33989d957b7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CollateralDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CollateralAxis_a1662a07-6dae-4ba3-87cd-b33989d957b7" xlink:to="loc_us-gaap_CollateralDomain_a1662a07-6dae-4ba3-87cd-b33989d957b7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralDomain_37c36b1b-986b-4533-83f5-74771f719de3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CollateralDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CollateralAxis_a1662a07-6dae-4ba3-87cd-b33989d957b7" xlink:to="loc_us-gaap_CollateralDomain_37c36b1b-986b-4533-83f5-74771f719de3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_AllAssetsIncludingIntellectualPropertyMember_3dbb1057-4399-4105-9a59-a92be1d690d9" xlink:href="htgc-20240630.xsd#htgc_AllAssetsIncludingIntellectualPropertyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_37c36b1b-986b-4533-83f5-74771f719de3" xlink:to="loc_htgc_AllAssetsIncludingIntellectualPropertyMember_3dbb1057-4399-4105-9a59-a92be1d690d9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_AllAssetsWithNegativePledgeOnIntellectualPropertyMember_2b827695-6a52-4f30-883c-b9773e136baf" xlink:href="htgc-20240630.xsd#htgc_AllAssetsWithNegativePledgeOnIntellectualPropertyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_37c36b1b-986b-4533-83f5-74771f719de3" xlink:to="loc_htgc_AllAssetsWithNegativePledgeOnIntellectualPropertyMember_2b827695-6a52-4f30-883c-b9773e136baf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_LastOutWithSecurityInterestInAllOfTheAssetsMember_0fb437f9-c950-4df5-8361-f9b2403fbe0c" xlink:href="htgc-20240630.xsd#htgc_LastOutWithSecurityInterestInAllOfTheAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_37c36b1b-986b-4533-83f5-74771f719de3" xlink:to="loc_htgc_LastOutWithSecurityInterestInAllOfTheAssetsMember_0fb437f9-c950-4df5-8361-f9b2403fbe0c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_52a0a394-ea47-43b1-a6a1-7c2cce5687b1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentsTable_95542843-bb24-4aca-a264-6b4e37119fd5" xlink:to="loc_us-gaap_InvestmentTypeAxis_52a0a394-ea47-43b1-a6a1-7c2cce5687b1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_52a0a394-ea47-43b1-a6a1-7c2cce5687b1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_52a0a394-ea47-43b1-a6a1-7c2cce5687b1" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_52a0a394-ea47-43b1-a6a1-7c2cce5687b1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_2419c090-4ad2-45b3-87f9-263cc2b636c0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_52a0a394-ea47-43b1-a6a1-7c2cce5687b1" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_2419c090-4ad2-45b3-87f9-263cc2b636c0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SeniorSecuredFirstLienMember_bae4f367-0fa5-4729-9849-e3a47861926a" xlink:href="htgc-20240630.xsd#htgc_SeniorSecuredFirstLienMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_2419c090-4ad2-45b3-87f9-263cc2b636c0" xlink:to="loc_htgc_SeniorSecuredFirstLienMember_bae4f367-0fa5-4729-9849-e3a47861926a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SecondLienMember_66fd8089-95db-4099-818f-324e43cb998b" xlink:href="htgc-20240630.xsd#htgc_SecondLienMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_2419c090-4ad2-45b3-87f9-263cc2b636c0" xlink:to="loc_htgc_SecondLienMember_66fd8089-95db-4099-818f-324e43cb998b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_UnsecuredMember_5386be43-1f37-49f6-8dcd-7fa31d7b7a1a" xlink:href="htgc-20240630.xsd#htgc_UnsecuredMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_2419c090-4ad2-45b3-87f9-263cc2b636c0" xlink:to="loc_htgc_UnsecuredMember_5386be43-1f37-49f6-8dcd-7fa31d7b7a1a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_85838a23-3733-4baf-95eb-c234ba4815c1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentsTable_95542843-bb24-4aca-a264-6b4e37119fd5" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_85838a23-3733-4baf-95eb-c234ba4815c1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_85838a23-3733-4baf-95eb-c234ba4815c1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_85838a23-3733-4baf-95eb-c234ba4815c1" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_85838a23-3733-4baf-95eb-c234ba4815c1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_8411c153-7ffa-4ff6-99c9-e7e633e5ebe3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_85838a23-3733-4baf-95eb-c234ba4815c1" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_8411c153-7ffa-4ff6-99c9-e7e633e5ebe3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CollateralTypeConcentrationRiskMember_ffd578c1-e564-4816-8336-75a33343abf4" xlink:href="htgc-20240630.xsd#htgc_CollateralTypeConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_8411c153-7ffa-4ff6-99c9-e7e633e5ebe3" xlink:to="loc_htgc_CollateralTypeConcentrationRiskMember_ffd578c1-e564-4816-8336-75a33343abf4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_500388f6-7e3d-43d6-94a7-66f967776444" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_66772bec-7a20-4df6-9e08-a552f6a2d702" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_500388f6-7e3d-43d6-94a7-66f967776444" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/InvestmentsScheduleofDerivativeInstrumentsDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#InvestmentsScheduleofDerivativeInstrumentsDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/InvestmentsScheduleofDerivativeInstrumentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_4428ffb5-6edf-4c76-8dc4-42386d92943f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SummaryOfInvestmentHoldingsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_InvestmentHoldingTable_87c62f3e-df83-4201-81ea-ba78f4b8099d" xlink:href="htgc-20240630.xsd#htgc_InvestmentHoldingTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_4428ffb5-6edf-4c76-8dc4-42386d92943f" xlink:to="loc_htgc_InvestmentHoldingTable_87c62f3e-df83-4201-81ea-ba78f4b8099d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_0c556906-bdcc-45db-a49b-603068c201b7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_htgc_InvestmentHoldingTable_87c62f3e-df83-4201-81ea-ba78f4b8099d" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_0c556906-bdcc-45db-a49b-603068c201b7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_0c556906-bdcc-45db-a49b-603068c201b7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_0c556906-bdcc-45db-a49b-603068c201b7" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_0c556906-bdcc-45db-a49b-603068c201b7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_f17f06a1-d30a-4cb7-a0cc-f77f69dfc62d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_0c556906-bdcc-45db-a49b-603068c201b7" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_f17f06a1-d30a-4cb7-a0cc-f77f69dfc62d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeForwardMember_3cccac48-9b39-447c-bb12-e147170bdaa1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignExchangeForwardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_f17f06a1-d30a-4cb7-a0cc-f77f69dfc62d" xlink:to="loc_us-gaap_ForeignExchangeForwardMember_3cccac48-9b39-447c-bb12-e147170bdaa1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_a8232009-f277-4c57-879c-83f964ae488e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BalanceSheetLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_htgc_InvestmentHoldingTable_87c62f3e-df83-4201-81ea-ba78f4b8099d" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_a8232009-f277-4c57-879c-83f964ae488e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_a8232009-f277-4c57-879c-83f964ae488e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_a8232009-f277-4c57-879c-83f964ae488e" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_a8232009-f277-4c57-879c-83f964ae488e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_291df635-e89e-4943-bbe1-6058ed940069" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_a8232009-f277-4c57-879c-83f964ae488e" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_291df635-e89e-4943-bbe1-6058ed940069" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsMember_cbcdad56-8212-4a57-ac5d-1e866aa5db49" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_291df635-e89e-4943-bbe1-6058ed940069" xlink:to="loc_us-gaap_OtherAssetsMember_cbcdad56-8212-4a57-ac5d-1e866aa5db49" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesMember_03751a7f-0add-4e6f-9b46-3757c4b75fa2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_291df635-e89e-4943-bbe1-6058ed940069" xlink:to="loc_us-gaap_AccountsPayableAndAccruedLiabilitiesMember_03751a7f-0add-4e6f-9b46-3757c4b75fa2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeAsset_37009277-607a-44fc-b2f5-503203e8cf36" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeFairValueOfDerivativeAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_4428ffb5-6edf-4c76-8dc4-42386d92943f" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeAsset_37009277-607a-44fc-b2f5-503203e8cf36" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_0fd5b985-62c7-4cef-b62f-5d283aa7be60" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeFairValueOfDerivativeLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_4428ffb5-6edf-4c76-8dc4-42386d92943f" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_0fd5b985-62c7-4cef-b62f-5d283aa7be60" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DerivativeAssetLiabilitySubjectToMasterNettingArrangementBeforeOffset_45801a84-675a-45e2-90e6-858cd73a9b0f" xlink:href="htgc-20240630.xsd#htgc_DerivativeAssetLiabilitySubjectToMasterNettingArrangementBeforeOffset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_4428ffb5-6edf-4c76-8dc4-42386d92943f" xlink:to="loc_htgc_DerivativeAssetLiabilitySubjectToMasterNettingArrangementBeforeOffset_45801a84-675a-45e2-90e6-858cd73a9b0f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnSaleOfDerivatives_5b6da4f2-6b86-4a65-bde3-354fcb6e4aed" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GainLossOnSaleOfDerivatives"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_4428ffb5-6edf-4c76-8dc4-42386d92943f" xlink:to="loc_us-gaap_GainLossOnSaleOfDerivatives_5b6da4f2-6b86-4a65-bde3-354fcb6e4aed" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossOnDerivatives_3edbd27d-c296-4a42-b944-72e15d0cc16d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnrealizedGainLossOnDerivatives"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_4428ffb5-6edf-4c76-8dc4-42386d92943f" xlink:to="loc_us-gaap_UnrealizedGainLossOnDerivatives_3edbd27d-c296-4a42-b944-72e15d0cc16d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealizedAndUnrealizedGainLossInvestmentAndDerivativeOperatingAfterTax_5a7e2b31-892f-4a2c-9470-5d240a38c128" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RealizedAndUnrealizedGainLossInvestmentAndDerivativeOperatingAfterTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_4428ffb5-6edf-4c76-8dc4-42386d92943f" xlink:to="loc_us-gaap_RealizedAndUnrealizedGainLossInvestmentAndDerivativeOperatingAfterTax_5a7e2b31-892f-4a2c-9470-5d240a38c128" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/InvestmentsScheduleofInvestmentInterestIncomeandFeeIncomeDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#InvestmentsScheduleofInvestmentInterestIncomeandFeeIncomeDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/InvestmentsScheduleofInvestmentInterestIncomeandFeeIncomeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentsLineItems_ac05da08-deda-4e1f-8ef7-79c76442f14c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfInvestmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentsTable_b62452b5-b379-482d-87b3-5a7d8e90a092" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfInvestmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_ac05da08-deda-4e1f-8ef7-79c76442f14c" xlink:to="loc_us-gaap_ScheduleOfInvestmentsTable_b62452b5-b379-482d-87b3-5a7d8e90a092" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_a0d997fd-f61e-4d73-947e-b2d7da25ebb5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentsTable_b62452b5-b379-482d-87b3-5a7d8e90a092" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_a0d997fd-f61e-4d73-947e-b2d7da25ebb5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_a0d997fd-f61e-4d73-947e-b2d7da25ebb5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_a0d997fd-f61e-4d73-947e-b2d7da25ebb5" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_a0d997fd-f61e-4d73-947e-b2d7da25ebb5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_c282b03b-87d1-4ace-aca4-f36d5de367ed" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_a0d997fd-f61e-4d73-947e-b2d7da25ebb5" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_c282b03b-87d1-4ace-aca4-f36d5de367ed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ContractualInterestIncomeMember_67eb84b8-32ce-480d-8045-32082a86ffbb" xlink:href="htgc-20240630.xsd#htgc_ContractualInterestIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_c282b03b-87d1-4ace-aca4-f36d5de367ed" xlink:to="loc_htgc_ContractualInterestIncomeMember_67eb84b8-32ce-480d-8045-32082a86ffbb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ExitFeeMember_7d6bc97f-c082-48b1-9545-c5cf539eab1c" xlink:href="htgc-20240630.xsd#htgc_ExitFeeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_c282b03b-87d1-4ace-aca4-f36d5de367ed" xlink:to="loc_htgc_ExitFeeMember_7d6bc97f-c082-48b1-9545-c5cf539eab1c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_PIKInterestMember_2ce2b7e7-c022-4d82-a0d3-c41fb7759db7" xlink:href="htgc-20240630.xsd#htgc_PIKInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_c282b03b-87d1-4ace-aca4-f36d5de367ed" xlink:to="loc_htgc_PIKInterestMember_2ce2b7e7-c022-4d82-a0d3-c41fb7759db7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DividendIncomeMember_0bca98f4-33d4-40ac-a9a8-09f0a0e4128d" xlink:href="htgc-20240630.xsd#htgc_DividendIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_c282b03b-87d1-4ace-aca4-f36d5de367ed" xlink:to="loc_htgc_DividendIncomeMember_0bca98f4-33d4-40ac-a9a8-09f0a0e4128d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_OtherInterestIncomeMember_87115a12-cc94-41e9-918e-85713ebafb50" xlink:href="htgc-20240630.xsd#htgc_OtherInterestIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_c282b03b-87d1-4ace-aca4-f36d5de367ed" xlink:to="loc_htgc_OtherInterestIncomeMember_87115a12-cc94-41e9-918e-85713ebafb50" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_RecurringFeeIncomeMember_2c6234ea-9689-4764-a594-5d7eb508a511" xlink:href="htgc-20240630.xsd#htgc_RecurringFeeIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_c282b03b-87d1-4ace-aca4-f36d5de367ed" xlink:to="loc_htgc_RecurringFeeIncomeMember_2c6234ea-9689-4764-a594-5d7eb508a511" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_AcceleratedFeeIncomeExpiredCommitmentsMember_38acac5c-43c6-4242-85d4-de8db2918d3a" xlink:href="htgc-20240630.xsd#htgc_AcceleratedFeeIncomeExpiredCommitmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_c282b03b-87d1-4ace-aca4-f36d5de367ed" xlink:to="loc_htgc_AcceleratedFeeIncomeExpiredCommitmentsMember_38acac5c-43c6-4242-85d4-de8db2918d3a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_AcceleratedFeeIncomeEarlyRepaymentsMember_fa0b7628-a471-41b9-be8d-9478ace82680" xlink:href="htgc-20240630.xsd#htgc_AcceleratedFeeIncomeEarlyRepaymentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_c282b03b-87d1-4ace-aca4-f36d5de367ed" xlink:to="loc_htgc_AcceleratedFeeIncomeEarlyRepaymentsMember_fa0b7628-a471-41b9-be8d-9478ace82680" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndDividendIncomeOperating_cca42abb-6de3-4bcc-8a12-d0b33544b181" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestAndDividendIncomeOperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_ac05da08-deda-4e1f-8ef7-79c76442f14c" xlink:to="loc_us-gaap_InterestAndDividendIncomeOperating_cca42abb-6de3-4bcc-8a12-d0b33544b181" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FeeIncome_005b6982-9763-4f9c-817d-d4d6860916d2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FeeIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_ac05da08-deda-4e1f-8ef7-79c76442f14c" xlink:to="loc_us-gaap_FeeIncome_005b6982-9763-4f9c-817d-d4d6860916d2" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/InvestmentsScheduleofUnamortizedCapitalizedFeeIncomeDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#InvestmentsScheduleofUnamortizedCapitalizedFeeIncomeDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/InvestmentsScheduleofUnamortizedCapitalizedFeeIncomeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_1005f112-3c10-4dc6-9b45-ce9a9c40de2f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentsTable_057bb0ba-ed23-412e-9ce8-db832068e8af" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfInvestmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_1005f112-3c10-4dc6-9b45-ce9a9c40de2f" xlink:to="loc_us-gaap_ScheduleOfInvestmentsTable_057bb0ba-ed23-412e-9ce8-db832068e8af" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis_ffc690d3-3553-4613-bfc1-3e032e4e3a1a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentsTable_057bb0ba-ed23-412e-9ce8-db832068e8af" xlink:to="loc_us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis_ffc690d3-3553-4613-bfc1-3e032e4e3a1a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivableTypeDomain_ffc690d3-3553-4613-bfc1-3e032e4e3a1a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ReceivableTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis_ffc690d3-3553-4613-bfc1-3e032e4e3a1a" xlink:to="loc_us-gaap_ReceivableTypeDomain_ffc690d3-3553-4613-bfc1-3e032e4e3a1a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivableTypeDomain_fd37e679-e150-4e57-bbf6-ece2ee67c420" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ReceivableTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis_ffc690d3-3553-4613-bfc1-3e032e4e3a1a" xlink:to="loc_us-gaap_ReceivableTypeDomain_fd37e679-e150-4e57-bbf6-ece2ee67c420" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_IncludedInCostMember_3235d646-2846-405b-8426-f8be4945fa37" xlink:href="htgc-20240630.xsd#htgc_IncludedInCostMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReceivableTypeDomain_fd37e679-e150-4e57-bbf6-ece2ee67c420" xlink:to="loc_htgc_IncludedInCostMember_3235d646-2846-405b-8426-f8be4945fa37" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DeferredFeesMember_53818243-36a8-468c-a9a5-8ed4e75938f5" xlink:href="htgc-20240630.xsd#htgc_DeferredFeesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReceivableTypeDomain_fd37e679-e150-4e57-bbf6-ece2ee67c420" xlink:to="loc_htgc_DeferredFeesMember_53818243-36a8-468c-a9a5-8ed4e75938f5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_UnamortizedFeeIncome_ea6b2b58-157a-47d2-8827-2d93b11e5edd" xlink:href="htgc-20240630.xsd#htgc_UnamortizedFeeIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_1005f112-3c10-4dc6-9b45-ce9a9c40de2f" xlink:to="loc_htgc_UnamortizedFeeIncome_ea6b2b58-157a-47d2-8827-2d93b11e5edd" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/InvestmentsScheduleofLoanExitFeesReceivableDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#InvestmentsScheduleofLoanExitFeesReceivableDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/InvestmentsScheduleofLoanExitFeesReceivableDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_28ec1411-1d36-4857-a1d2-1a2db2780ffc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentsTable_b8b10796-9bcd-4651-ad81-4f88944ad221" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfInvestmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_28ec1411-1d36-4857-a1d2-1a2db2780ffc" xlink:to="loc_us-gaap_ScheduleOfInvestmentsTable_b8b10796-9bcd-4651-ad81-4f88944ad221" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis_4bbaa98c-f0ee-4b6b-b6cd-afd52e2e969e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentsTable_b8b10796-9bcd-4651-ad81-4f88944ad221" xlink:to="loc_us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis_4bbaa98c-f0ee-4b6b-b6cd-afd52e2e969e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivableTypeDomain_4bbaa98c-f0ee-4b6b-b6cd-afd52e2e969e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ReceivableTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis_4bbaa98c-f0ee-4b6b-b6cd-afd52e2e969e" xlink:to="loc_us-gaap_ReceivableTypeDomain_4bbaa98c-f0ee-4b6b-b6cd-afd52e2e969e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivableTypeDomain_9c01b9de-75df-4bd6-a98f-96fb52ca4f05" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ReceivableTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis_4bbaa98c-f0ee-4b6b-b6cd-afd52e2e969e" xlink:to="loc_us-gaap_ReceivableTypeDomain_9c01b9de-75df-4bd6-a98f-96fb52ca4f05" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_IncludedInCostMember_23b11a02-1091-4adb-9bb2-79befdd0759a" xlink:href="htgc-20240630.xsd#htgc_IncludedInCostMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReceivableTypeDomain_9c01b9de-75df-4bd6-a98f-96fb52ca4f05" xlink:to="loc_htgc_IncludedInCostMember_23b11a02-1091-4adb-9bb2-79befdd0759a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DeferredFeesMember_8bda124c-eb8d-4e15-b370-2677b933556c" xlink:href="htgc-20240630.xsd#htgc_DeferredFeesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReceivableTypeDomain_9c01b9de-75df-4bd6-a98f-96fb52ca4f05" xlink:to="loc_htgc_DeferredFeesMember_8bda124c-eb8d-4e15-b370-2677b933556c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ExitFeesReceivables_52b6858a-bd87-4c6a-89e8-97fe7137ec86" xlink:href="htgc-20240630.xsd#htgc_ExitFeesReceivables"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_28ec1411-1d36-4857-a1d2-1a2db2780ffc" xlink:to="loc_htgc_ExitFeesReceivables_52b6858a-bd87-4c6a-89e8-97fe7137ec86" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/DebtScheduleofAvailableandOutstandingDebtDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#DebtScheduleofAvailableandOutstandingDebtDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/DebtScheduleofAvailableandOutstandingDebtDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_133b11f5-4582-49d1-8f97-60fbdab80248" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_7ad943b1-67ec-4f4b-845c-3c9be0c77fb4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_133b11f5-4582-49d1-8f97-60fbdab80248" xlink:to="loc_us-gaap_DebtInstrumentTable_7ad943b1-67ec-4f4b-845c-3c9be0c77fb4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_a351b527-100f-4e5b-8b8f-ea08157b79f7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_7ad943b1-67ec-4f4b-845c-3c9be0c77fb4" xlink:to="loc_us-gaap_DebtInstrumentAxis_a351b527-100f-4e5b-8b8f-ea08157b79f7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_a351b527-100f-4e5b-8b8f-ea08157b79f7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_a351b527-100f-4e5b-8b8f-ea08157b79f7" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_a351b527-100f-4e5b-8b8f-ea08157b79f7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_7527bc66-807d-4dad-9b88-a0b187b85ae5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_a351b527-100f-4e5b-8b8f-ea08157b79f7" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_7527bc66-807d-4dad-9b88-a0b187b85ae5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesMember_2eb17f96-d492-4eef-b2ba-73cf2ac19fa1" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7527bc66-807d-4dad-9b88-a0b187b85ae5" xlink:to="loc_htgc_SBADebenturesMember_2eb17f96-d492-4eef-b2ba-73cf2ac19fa1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JulyTwoThousandTwentyFourNotesMember_49943a79-0a8f-4e33-8a57-483e32d8061e" xlink:href="htgc-20240630.xsd#htgc_JulyTwoThousandTwentyFourNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7527bc66-807d-4dad-9b88-a0b187b85ae5" xlink:to="loc_htgc_JulyTwoThousandTwentyFourNotesMember_49943a79-0a8f-4e33-8a57-483e32d8061e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_FebruaryTwoThousandTwentyFiveNotesMember_009d099c-72c6-4967-a107-fdac45218489" xlink:href="htgc-20240630.xsd#htgc_FebruaryTwoThousandTwentyFiveNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7527bc66-807d-4dad-9b88-a0b187b85ae5" xlink:to="loc_htgc_FebruaryTwoThousandTwentyFiveNotesMember_009d099c-72c6-4967-a107-fdac45218489" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JuneTwoThousandTwentyFiveNotesMember_9ffae0cf-92e5-4ca5-9f5a-502e02fc5f62" xlink:href="htgc-20240630.xsd#htgc_JuneTwoThousandTwentyFiveNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7527bc66-807d-4dad-9b88-a0b187b85ae5" xlink:to="loc_htgc_JuneTwoThousandTwentyFiveNotesMember_9ffae0cf-92e5-4ca5-9f5a-502e02fc5f62" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JuneTwoThousandTwentyFiveThreeYearNotesMember_55f30178-25eb-4766-84fc-e3e681c6ef09" xlink:href="htgc-20240630.xsd#htgc_JuneTwoThousandTwentyFiveThreeYearNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7527bc66-807d-4dad-9b88-a0b187b85ae5" xlink:to="loc_htgc_JuneTwoThousandTwentyFiveThreeYearNotesMember_55f30178-25eb-4766-84fc-e3e681c6ef09" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MarchTwoThousandTwentySixANotesMember_b12b3003-0135-4361-9ce6-ca295a9dc6ae" xlink:href="htgc-20240630.xsd#htgc_MarchTwoThousandTwentySixANotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7527bc66-807d-4dad-9b88-a0b187b85ae5" xlink:to="loc_htgc_MarchTwoThousandTwentySixANotesMember_b12b3003-0135-4361-9ce6-ca295a9dc6ae" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MarchTwoThousandTwentySixBNotesMember_fb52d0aa-3f41-4dcb-b081-160272ae9ab0" xlink:href="htgc-20240630.xsd#htgc_MarchTwoThousandTwentySixBNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7527bc66-807d-4dad-9b88-a0b187b85ae5" xlink:to="loc_htgc_MarchTwoThousandTwentySixBNotesMember_fb52d0aa-3f41-4dcb-b081-160272ae9ab0" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SeptemberTwoThousandTwentySixNotesMember_101e0362-e4ef-49d5-883e-f46f40426eab" xlink:href="htgc-20240630.xsd#htgc_SeptemberTwoThousandTwentySixNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7527bc66-807d-4dad-9b88-a0b187b85ae5" xlink:to="loc_htgc_SeptemberTwoThousandTwentySixNotesMember_101e0362-e4ef-49d5-883e-f46f40426eab" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JanuaryTwoThousandTwentySevenNotesMember_6bd1354b-096d-4d98-9044-5742d6ce9273" xlink:href="htgc-20240630.xsd#htgc_JanuaryTwoThousandTwentySevenNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7527bc66-807d-4dad-9b88-a0b187b85ae5" xlink:to="loc_htgc_JanuaryTwoThousandTwentySevenNotesMember_6bd1354b-096d-4d98-9044-5742d6ce9273" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TwoThousandThirtyOneAssetBackedNotesMember_ddb6238b-9267-46aa-8bd2-2db0b0c49121" xlink:href="htgc-20240630.xsd#htgc_TwoThousandThirtyOneAssetBackedNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7527bc66-807d-4dad-9b88-a0b187b85ae5" xlink:to="loc_htgc_TwoThousandThirtyOneAssetBackedNotesMember_ddb6238b-9267-46aa-8bd2-2db0b0c49121" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TwoThousandThirtyThreeNotesMember_817cef97-5330-4a8b-9820-6809df350866" xlink:href="htgc-20240630.xsd#htgc_TwoThousandThirtyThreeNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7527bc66-807d-4dad-9b88-a0b187b85ae5" xlink:to="loc_htgc_TwoThousandThirtyThreeNotesMember_817cef97-5330-4a8b-9820-6809df350866" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MUFGBankFacilityMember_d8320041-9c42-4e18-9938-cf5ce40c86c8" xlink:href="htgc-20240630.xsd#htgc_MUFGBankFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7527bc66-807d-4dad-9b88-a0b187b85ae5" xlink:to="loc_htgc_MUFGBankFacilityMember_d8320041-9c42-4e18-9938-cf5ce40c86c8" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SMBCFacilityMember_32aaa8fa-a836-48da-a027-dd4989a97c18" xlink:href="htgc-20240630.xsd#htgc_SMBCFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7527bc66-807d-4dad-9b88-a0b187b85ae5" xlink:to="loc_htgc_SMBCFacilityMember_32aaa8fa-a836-48da-a027-dd4989a97c18" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_de28ef11-a965-4b4c-8ba1-f1fb1953415e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_7ad943b1-67ec-4f4b-845c-3c9be0c77fb4" xlink:to="loc_us-gaap_CreditFacilityAxis_de28ef11-a965-4b4c-8ba1-f1fb1953415e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_de28ef11-a965-4b4c-8ba1-f1fb1953415e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_de28ef11-a965-4b4c-8ba1-f1fb1953415e" xlink:to="loc_us-gaap_CreditFacilityDomain_de28ef11-a965-4b4c-8ba1-f1fb1953415e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_84bab751-0667-462d-96cb-4eef872fcbb3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_de28ef11-a965-4b4c-8ba1-f1fb1953415e" xlink:to="loc_us-gaap_CreditFacilityDomain_84bab751-0667-462d-96cb-4eef872fcbb3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SmbcLcFacilityMember_71ef78ee-2626-459d-a90e-65b24093954f" xlink:href="htgc-20240630.xsd#htgc_SmbcLcFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_84bab751-0667-462d-96cb-4eef872fcbb3" xlink:to="loc_htgc_SmbcLcFacilityMember_71ef78ee-2626-459d-a90e-65b24093954f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_ef6a7e0d-6624-4bf1-a04f-0ad973ffc5c4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_133b11f5-4582-49d1-8f97-60fbdab80248" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_ef6a7e0d-6624-4bf1-a04f-0ad973ffc5c4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_d48dd47f-f897-4eff-88f0-92a687f7d110" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_133b11f5-4582-49d1-8f97-60fbdab80248" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_d48dd47f-f897-4eff-88f0-92a687f7d110" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_f77fd722-89ae-4c24-bf3d-2667e1a22a49" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_133b11f5-4582-49d1-8f97-60fbdab80248" xlink:to="loc_us-gaap_LongTermDebt_f77fd722-89ae-4c24-bf3d-2667e1a22a49" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_5fd60075-b720-4a4f-a168-a21701c83a5d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_133b11f5-4582-49d1-8f97-60fbdab80248" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_5fd60075-b720-4a4f-a168-a21701c83a5d" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/DebtScheduleofDebtIssuanceCostsNetofaccumulatedAmortizationDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#DebtScheduleofDebtIssuanceCostsNetofaccumulatedAmortizationDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/DebtScheduleofDebtIssuanceCostsNetofaccumulatedAmortizationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_b317c388-d9e4-4a16-953f-f72d063aa8f7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_7545e4ea-36a8-4cc5-b061-6589db932f58" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_b317c388-d9e4-4a16-953f-f72d063aa8f7" xlink:to="loc_us-gaap_DebtInstrumentTable_7545e4ea-36a8-4cc5-b061-6589db932f58" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_806f0f7e-33b4-42c0-a812-77abf52017d0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_7545e4ea-36a8-4cc5-b061-6589db932f58" xlink:to="loc_us-gaap_DebtInstrumentAxis_806f0f7e-33b4-42c0-a812-77abf52017d0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_806f0f7e-33b4-42c0-a812-77abf52017d0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_806f0f7e-33b4-42c0-a812-77abf52017d0" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_806f0f7e-33b4-42c0-a812-77abf52017d0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_496b67c6-44c4-4f66-93ae-59590fb4594f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_806f0f7e-33b4-42c0-a812-77abf52017d0" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_496b67c6-44c4-4f66-93ae-59590fb4594f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesMember_486d616e-b848-468e-8ba2-710a02c76394" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_496b67c6-44c4-4f66-93ae-59590fb4594f" xlink:to="loc_htgc_SBADebenturesMember_486d616e-b848-468e-8ba2-710a02c76394" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JulyTwoThousandTwentyFourNotesMember_6339e74d-cc30-4a8e-984b-95e75677df83" xlink:href="htgc-20240630.xsd#htgc_JulyTwoThousandTwentyFourNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_496b67c6-44c4-4f66-93ae-59590fb4594f" xlink:to="loc_htgc_JulyTwoThousandTwentyFourNotesMember_6339e74d-cc30-4a8e-984b-95e75677df83" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_FebruaryTwoThousandTwentyFiveNotesMember_3d5fbcd0-645e-4e53-aeac-b487676b36b6" xlink:href="htgc-20240630.xsd#htgc_FebruaryTwoThousandTwentyFiveNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_496b67c6-44c4-4f66-93ae-59590fb4594f" xlink:to="loc_htgc_FebruaryTwoThousandTwentyFiveNotesMember_3d5fbcd0-645e-4e53-aeac-b487676b36b6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JuneTwoThousandTwentyFiveNotesMember_216f4c06-b126-4fca-9f6d-e6bd22eae920" xlink:href="htgc-20240630.xsd#htgc_JuneTwoThousandTwentyFiveNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_496b67c6-44c4-4f66-93ae-59590fb4594f" xlink:to="loc_htgc_JuneTwoThousandTwentyFiveNotesMember_216f4c06-b126-4fca-9f6d-e6bd22eae920" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JuneTwoThousandTwentyFiveThreeYearNotesMember_99f4867e-43ef-40f2-9ec4-ff13147f9e94" xlink:href="htgc-20240630.xsd#htgc_JuneTwoThousandTwentyFiveThreeYearNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_496b67c6-44c4-4f66-93ae-59590fb4594f" xlink:to="loc_htgc_JuneTwoThousandTwentyFiveThreeYearNotesMember_99f4867e-43ef-40f2-9ec4-ff13147f9e94" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MarchTwoThousandTwentySixANotesMember_f1d4eef6-c508-4a80-aaee-02f7ebef8428" xlink:href="htgc-20240630.xsd#htgc_MarchTwoThousandTwentySixANotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_496b67c6-44c4-4f66-93ae-59590fb4594f" xlink:to="loc_htgc_MarchTwoThousandTwentySixANotesMember_f1d4eef6-c508-4a80-aaee-02f7ebef8428" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MarchTwoThousandTwentySixBNotesMember_3a0f6be0-27bc-4032-8bdd-0ffc29fc0029" xlink:href="htgc-20240630.xsd#htgc_MarchTwoThousandTwentySixBNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_496b67c6-44c4-4f66-93ae-59590fb4594f" xlink:to="loc_htgc_MarchTwoThousandTwentySixBNotesMember_3a0f6be0-27bc-4032-8bdd-0ffc29fc0029" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SeptemberTwoThousandTwentySixNotesMember_d32a1a1f-dac7-4c0d-baf7-31e700b6ac88" xlink:href="htgc-20240630.xsd#htgc_SeptemberTwoThousandTwentySixNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_496b67c6-44c4-4f66-93ae-59590fb4594f" xlink:to="loc_htgc_SeptemberTwoThousandTwentySixNotesMember_d32a1a1f-dac7-4c0d-baf7-31e700b6ac88" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JanuaryTwoThousandTwentySevenNotesMember_811e519c-a2f7-4eef-ae9b-3fb3cab14067" xlink:href="htgc-20240630.xsd#htgc_JanuaryTwoThousandTwentySevenNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_496b67c6-44c4-4f66-93ae-59590fb4594f" xlink:to="loc_htgc_JanuaryTwoThousandTwentySevenNotesMember_811e519c-a2f7-4eef-ae9b-3fb3cab14067" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TwoThousandThirtyOneAssetBackedNotesMember_778db090-ea55-41b3-aedc-c278badebb7a" xlink:href="htgc-20240630.xsd#htgc_TwoThousandThirtyOneAssetBackedNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_496b67c6-44c4-4f66-93ae-59590fb4594f" xlink:to="loc_htgc_TwoThousandThirtyOneAssetBackedNotesMember_778db090-ea55-41b3-aedc-c278badebb7a" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TwoThousandThirtyThreeNotesMember_5ffd5e40-4dcb-45a1-b899-1d38800b757a" xlink:href="htgc-20240630.xsd#htgc_TwoThousandThirtyThreeNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_496b67c6-44c4-4f66-93ae-59590fb4594f" xlink:to="loc_htgc_TwoThousandThirtyThreeNotesMember_5ffd5e40-4dcb-45a1-b899-1d38800b757a" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MUFGBankFacilityMember_7bba2882-4754-42ca-a27f-549d3b199247" xlink:href="htgc-20240630.xsd#htgc_MUFGBankFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_496b67c6-44c4-4f66-93ae-59590fb4594f" xlink:to="loc_htgc_MUFGBankFacilityMember_7bba2882-4754-42ca-a27f-549d3b199247" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SMBCFacilityMember_8daf55f4-11a5-464a-b8cd-1917f0148bac" xlink:href="htgc-20240630.xsd#htgc_SMBCFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_496b67c6-44c4-4f66-93ae-59590fb4594f" xlink:to="loc_htgc_SMBCFacilityMember_8daf55f4-11a5-464a-b8cd-1917f0148bac" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_62910117-c2f8-4500-9847-6801b1ddc1f9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredFinanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_b317c388-d9e4-4a16-953f-f72d063aa8f7" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_62910117-c2f8-4500-9847-6801b1ddc1f9" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/DebtComponentsofInterestExpenseRelatedFeesandCashPaidforInterestExpenseforDebtDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#DebtComponentsofInterestExpenseRelatedFeesandCashPaidforInterestExpenseforDebtDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/DebtComponentsofInterestExpenseRelatedFeesandCashPaidforInterestExpenseforDebtDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_b5eff74e-d83a-4672-ad9b-7f1b018e5081" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_9bdd7776-c66a-4349-933c-220d5c6a70eb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_b5eff74e-d83a-4672-ad9b-7f1b018e5081" xlink:to="loc_us-gaap_DebtInstrumentTable_9bdd7776-c66a-4349-933c-220d5c6a70eb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_6e86aa45-2fb0-438f-afd9-cc80b12162c7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_9bdd7776-c66a-4349-933c-220d5c6a70eb" xlink:to="loc_us-gaap_DebtInstrumentAxis_6e86aa45-2fb0-438f-afd9-cc80b12162c7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_6e86aa45-2fb0-438f-afd9-cc80b12162c7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_6e86aa45-2fb0-438f-afd9-cc80b12162c7" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_6e86aa45-2fb0-438f-afd9-cc80b12162c7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_69e58c52-77b3-446a-aba1-9d6c2b34c3ee" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_6e86aa45-2fb0-438f-afd9-cc80b12162c7" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_69e58c52-77b3-446a-aba1-9d6c2b34c3ee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesMember_ab223352-c857-41c0-8f9e-35b7ceff5f79" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_69e58c52-77b3-446a-aba1-9d6c2b34c3ee" xlink:to="loc_htgc_SBADebenturesMember_ab223352-c857-41c0-8f9e-35b7ceff5f79" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JulyTwoThousandTwentyFourNotesMember_97422943-a66e-4546-903c-38fd56e1325a" xlink:href="htgc-20240630.xsd#htgc_JulyTwoThousandTwentyFourNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_69e58c52-77b3-446a-aba1-9d6c2b34c3ee" xlink:to="loc_htgc_JulyTwoThousandTwentyFourNotesMember_97422943-a66e-4546-903c-38fd56e1325a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_FebruaryTwoThousandTwentyFiveNotesMember_5a87c3c0-0b3c-4ede-9aad-070b67ad3971" xlink:href="htgc-20240630.xsd#htgc_FebruaryTwoThousandTwentyFiveNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_69e58c52-77b3-446a-aba1-9d6c2b34c3ee" xlink:to="loc_htgc_FebruaryTwoThousandTwentyFiveNotesMember_5a87c3c0-0b3c-4ede-9aad-070b67ad3971" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JuneTwoThousandTwentyFiveNotesMember_603a29cd-eabe-475b-9e29-a8af04c64c96" xlink:href="htgc-20240630.xsd#htgc_JuneTwoThousandTwentyFiveNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_69e58c52-77b3-446a-aba1-9d6c2b34c3ee" xlink:to="loc_htgc_JuneTwoThousandTwentyFiveNotesMember_603a29cd-eabe-475b-9e29-a8af04c64c96" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JuneTwoThousandTwentyFiveThreeYearNotesMember_e3568772-2e13-421d-9b95-be24eb668943" xlink:href="htgc-20240630.xsd#htgc_JuneTwoThousandTwentyFiveThreeYearNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_69e58c52-77b3-446a-aba1-9d6c2b34c3ee" xlink:to="loc_htgc_JuneTwoThousandTwentyFiveThreeYearNotesMember_e3568772-2e13-421d-9b95-be24eb668943" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MarchTwoThousandTwentySixANotesMember_4b6f6e58-a3db-44a2-a0ec-f655ba557a01" xlink:href="htgc-20240630.xsd#htgc_MarchTwoThousandTwentySixANotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_69e58c52-77b3-446a-aba1-9d6c2b34c3ee" xlink:to="loc_htgc_MarchTwoThousandTwentySixANotesMember_4b6f6e58-a3db-44a2-a0ec-f655ba557a01" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MarchTwoThousandTwentySixBNotesMember_f7661aea-506e-421b-8759-3bed3ee7da46" xlink:href="htgc-20240630.xsd#htgc_MarchTwoThousandTwentySixBNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_69e58c52-77b3-446a-aba1-9d6c2b34c3ee" xlink:to="loc_htgc_MarchTwoThousandTwentySixBNotesMember_f7661aea-506e-421b-8759-3bed3ee7da46" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SeptemberTwoThousandTwentySixNotesMember_cead9e02-be5a-4134-bdca-0fb2a29ab957" xlink:href="htgc-20240630.xsd#htgc_SeptemberTwoThousandTwentySixNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_69e58c52-77b3-446a-aba1-9d6c2b34c3ee" xlink:to="loc_htgc_SeptemberTwoThousandTwentySixNotesMember_cead9e02-be5a-4134-bdca-0fb2a29ab957" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JanuaryTwoThousandTwentySevenNotesMember_304beedc-600a-4f80-b40f-5cdfb3611d5b" xlink:href="htgc-20240630.xsd#htgc_JanuaryTwoThousandTwentySevenNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_69e58c52-77b3-446a-aba1-9d6c2b34c3ee" xlink:to="loc_htgc_JanuaryTwoThousandTwentySevenNotesMember_304beedc-600a-4f80-b40f-5cdfb3611d5b" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TwoThousandThirtyOneAssetBackedNotesMember_18d4a229-181a-45e7-a481-6d34ab4ddf08" xlink:href="htgc-20240630.xsd#htgc_TwoThousandThirtyOneAssetBackedNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_69e58c52-77b3-446a-aba1-9d6c2b34c3ee" xlink:to="loc_htgc_TwoThousandThirtyOneAssetBackedNotesMember_18d4a229-181a-45e7-a481-6d34ab4ddf08" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TwoThousandThirtyThreeNotesMember_05f43b40-e841-494b-84bc-87cd9705aa07" xlink:href="htgc-20240630.xsd#htgc_TwoThousandThirtyThreeNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_69e58c52-77b3-446a-aba1-9d6c2b34c3ee" xlink:to="loc_htgc_TwoThousandThirtyThreeNotesMember_05f43b40-e841-494b-84bc-87cd9705aa07" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MUFGBankFacilityMember_01e7018e-6829-482d-934d-b59e78d194e8" xlink:href="htgc-20240630.xsd#htgc_MUFGBankFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_69e58c52-77b3-446a-aba1-9d6c2b34c3ee" xlink:to="loc_htgc_MUFGBankFacilityMember_01e7018e-6829-482d-934d-b59e78d194e8" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SMBCFacilityMember_7a6b6c57-0070-4873-84b0-9c0645aff6ff" xlink:href="htgc-20240630.xsd#htgc_SMBCFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_69e58c52-77b3-446a-aba1-9d6c2b34c3ee" xlink:to="loc_htgc_SMBCFacilityMember_7a6b6c57-0070-4873-84b0-9c0645aff6ff" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseDebt_857c9f79-782a-46ea-a1d9-a43d172d693c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestExpenseDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_b5eff74e-d83a-4672-ad9b-7f1b018e5081" xlink:to="loc_us-gaap_InterestExpenseDebt_857c9f79-782a-46ea-a1d9-a43d172d693c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfFinancingCosts_972effe1-be27-4d60-86fe-3039aed9f459" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AmortizationOfFinancingCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_b5eff74e-d83a-4672-ad9b-7f1b018e5081" xlink:to="loc_us-gaap_AmortizationOfFinancingCosts_972effe1-be27-4d60-86fe-3039aed9f459" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoanPortfolioExpense_1a95c0c6-373f-4b60-8df4-b6ec681d517a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LoanPortfolioExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_b5eff74e-d83a-4672-ad9b-7f1b018e5081" xlink:to="loc_us-gaap_LoanPortfolioExpense_1a95c0c6-373f-4b60-8df4-b6ec681d517a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseOperating_b4a84a72-57e6-4643-a7d7-c44e29c23f61" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestExpenseOperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_b5eff74e-d83a-4672-ad9b-7f1b018e5081" xlink:to="loc_us-gaap_InterestExpenseOperating_b4a84a72-57e6-4643-a7d7-c44e29c23f61" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestPaidNet_d67b00a0-5c29-401b-a8d8-305991164577" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestPaidNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_b5eff74e-d83a-4672-ad9b-7f1b018e5081" xlink:to="loc_us-gaap_InterestPaidNet_d67b00a0-5c29-401b-a8d8-305991164577" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfDebtDiscountPremium_c6903c99-6573-452e-894a-737982c07686" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AmortizationOfDebtDiscountPremium"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_b5eff74e-d83a-4672-ad9b-7f1b018e5081" xlink:to="loc_us-gaap_AmortizationOfDebtDiscountPremium_c6903c99-6573-452e-894a-737982c07686" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/DebtScheduleofSBADebenturesOutstandingPrincipalBalancesDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#DebtScheduleofSBADebenturesOutstandingPrincipalBalancesDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/DebtScheduleofSBADebenturesOutstandingPrincipalBalancesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_9c9aaa9d-2ab5-4108-946d-22038122ee1c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_ad9b1a3f-1c1a-4f3e-ab96-03a846898585" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9c9aaa9d-2ab5-4108-946d-22038122ee1c" xlink:to="loc_us-gaap_DebtInstrumentTable_ad9b1a3f-1c1a-4f3e-ab96-03a846898585" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_7350b716-6494-4539-a7d5-552880c7341b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_ad9b1a3f-1c1a-4f3e-ab96-03a846898585" xlink:to="loc_us-gaap_DebtInstrumentAxis_7350b716-6494-4539-a7d5-552880c7341b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_7350b716-6494-4539-a7d5-552880c7341b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_7350b716-6494-4539-a7d5-552880c7341b" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_7350b716-6494-4539-a7d5-552880c7341b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_ab7585e9-2b35-427f-a606-a54ffedb29ff" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_7350b716-6494-4539-a7d5-552880c7341b" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_ab7585e9-2b35-427f-a606-a54ffedb29ff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesIssuedOnMarchTwentySixTwoThousandAndTwentyOneMember_95852106-535c-43a3-b0e5-7c975582e515" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesIssuedOnMarchTwentySixTwoThousandAndTwentyOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_ab7585e9-2b35-427f-a606-a54ffedb29ff" xlink:to="loc_htgc_SBADebenturesIssuedOnMarchTwentySixTwoThousandAndTwentyOneMember_95852106-535c-43a3-b0e5-7c975582e515" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesIssuedOnJuneTwentyFiveTwoThousandAndTwentyOneMember_f406b459-a05e-4bd5-93a6-46a7c47f7ab3" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesIssuedOnJuneTwentyFiveTwoThousandAndTwentyOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_ab7585e9-2b35-427f-a606-a54ffedb29ff" xlink:to="loc_htgc_SBADebenturesIssuedOnJuneTwentyFiveTwoThousandAndTwentyOneMember_f406b459-a05e-4bd5-93a6-46a7c47f7ab3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesIssuedOnJulyTwentyEightTwoThousandAndTwentyOneMember_a67e1734-93c6-435a-b5a9-4a842155fa08" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesIssuedOnJulyTwentyEightTwoThousandAndTwentyOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_ab7585e9-2b35-427f-a606-a54ffedb29ff" xlink:to="loc_htgc_SBADebenturesIssuedOnJulyTwentyEightTwoThousandAndTwentyOneMember_a67e1734-93c6-435a-b5a9-4a842155fa08" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesIssuedOnAugustTwentyTwoThousandAndTwentyOneMember_24df176e-4956-4229-b068-8321eab4de5e" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesIssuedOnAugustTwentyTwoThousandAndTwentyOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_ab7585e9-2b35-427f-a606-a54ffedb29ff" xlink:to="loc_htgc_SBADebenturesIssuedOnAugustTwentyTwoThousandAndTwentyOneMember_24df176e-4956-4229-b068-8321eab4de5e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesIssuedOnOctoberTwentyOneTwoThousandAndTwentyOneMember_e1b7f469-e2ce-4739-aa98-7abaa5e18c01" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesIssuedOnOctoberTwentyOneTwoThousandAndTwentyOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_ab7585e9-2b35-427f-a606-a54ffedb29ff" xlink:to="loc_htgc_SBADebenturesIssuedOnOctoberTwentyOneTwoThousandAndTwentyOneMember_e1b7f469-e2ce-4739-aa98-7abaa5e18c01" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesIssuedOnNovemberOneTwoThousandAndTwentyOneMember_d2470009-2300-4a85-9f34-c7e8fba3ccb4" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesIssuedOnNovemberOneTwoThousandAndTwentyOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_ab7585e9-2b35-427f-a606-a54ffedb29ff" xlink:to="loc_htgc_SBADebenturesIssuedOnNovemberOneTwoThousandAndTwentyOneMember_d2470009-2300-4a85-9f34-c7e8fba3ccb4" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesIssuedOnNovemberFifteenTwoThousandAndTwentyOneMember_41a8049a-ad8b-4205-b850-e120f78fc119" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesIssuedOnNovemberFifteenTwoThousandAndTwentyOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_ab7585e9-2b35-427f-a606-a54ffedb29ff" xlink:to="loc_htgc_SBADebenturesIssuedOnNovemberFifteenTwoThousandAndTwentyOneMember_41a8049a-ad8b-4205-b850-e120f78fc119" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesIssuedOnNovemberThirtyTwoThousandAndTwentyOneMember_175292dc-ea0b-4d6e-8eed-4bc9d4ed68e3" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesIssuedOnNovemberThirtyTwoThousandAndTwentyOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_ab7585e9-2b35-427f-a606-a54ffedb29ff" xlink:to="loc_htgc_SBADebenturesIssuedOnNovemberThirtyTwoThousandAndTwentyOneMember_175292dc-ea0b-4d6e-8eed-4bc9d4ed68e3" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesIssuedOnDecemberTwentyTwoThousandAndTwentyOneMember_cff0a363-d530-43fd-9d0d-b3f1d997a584" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesIssuedOnDecemberTwentyTwoThousandAndTwentyOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_ab7585e9-2b35-427f-a606-a54ffedb29ff" xlink:to="loc_htgc_SBADebenturesIssuedOnDecemberTwentyTwoThousandAndTwentyOneMember_cff0a363-d530-43fd-9d0d-b3f1d997a584" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesIssuedOnDecemberTwentyThreeTwoThousandAndTwentyOneMember_ea93fdc5-51e2-4947-8e00-ec972cbb5c80" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesIssuedOnDecemberTwentyThreeTwoThousandAndTwentyOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_ab7585e9-2b35-427f-a606-a54ffedb29ff" xlink:to="loc_htgc_SBADebenturesIssuedOnDecemberTwentyThreeTwoThousandAndTwentyOneMember_ea93fdc5-51e2-4947-8e00-ec972cbb5c80" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesIssuedOnDecemberTwentyEightTwoThousandAndTwentyOneMember_cb39f054-180b-490b-9d90-a6c116e6cba5" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesIssuedOnDecemberTwentyEightTwoThousandAndTwentyOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_ab7585e9-2b35-427f-a606-a54ffedb29ff" xlink:to="loc_htgc_SBADebenturesIssuedOnDecemberTwentyEightTwoThousandAndTwentyOneMember_cb39f054-180b-490b-9d90-a6c116e6cba5" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesIssuedOnJanuaryFourteenTwoThousandAndTwentyTwoMember_2739374d-9ad2-499b-a6b5-1c3220266a19" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesIssuedOnJanuaryFourteenTwoThousandAndTwentyTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_ab7585e9-2b35-427f-a606-a54ffedb29ff" xlink:to="loc_htgc_SBADebenturesIssuedOnJanuaryFourteenTwoThousandAndTwentyTwoMember_2739374d-9ad2-499b-a6b5-1c3220266a19" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesIssuedOnJanuaryTwentyOneTwoThousandAndTwentyTwoMember_87cda737-cd2c-4a44-b4b2-e57450a8965f" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesIssuedOnJanuaryTwentyOneTwoThousandAndTwentyTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_ab7585e9-2b35-427f-a606-a54ffedb29ff" xlink:to="loc_htgc_SBADebenturesIssuedOnJanuaryTwentyOneTwoThousandAndTwentyTwoMember_87cda737-cd2c-4a44-b4b2-e57450a8965f" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesMember_55b50bcc-7e2a-4885-b30c-f93c536600dd" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_ab7585e9-2b35-427f-a606-a54ffedb29ff" xlink:to="loc_htgc_SBADebenturesMember_55b50bcc-7e2a-4885-b30c-f93c536600dd" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentIssuanceDate1_7e53b423-2262-4d7f-8c47-58029decbca2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentIssuanceDate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9c9aaa9d-2ab5-4108-946d-22038122ee1c" xlink:to="loc_us-gaap_DebtInstrumentIssuanceDate1_7e53b423-2262-4d7f-8c47-58029decbca2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentMaturityDate_bba94e28-4428-4bab-a7ee-91d46fcb55de" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentMaturityDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9c9aaa9d-2ab5-4108-946d-22038122ee1c" xlink:to="loc_us-gaap_DebtInstrumentMaturityDate_bba94e28-4428-4bab-a7ee-91d46fcb55de" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_187d88fa-11db-49c9-9a9e-1d8c6eda668c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9c9aaa9d-2ab5-4108-946d-22038122ee1c" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_187d88fa-11db-49c9-9a9e-1d8c6eda668c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_22fe9aa2-9a9c-4d5b-91f4-9f22f2f28df8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9c9aaa9d-2ab5-4108-946d-22038122ee1c" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_22fe9aa2-9a9c-4d5b-91f4-9f22f2f28df8" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/DebtNarrativeDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#DebtNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/DebtNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_91821dba-11e5-4f11-bbdc-b65a7bfe3b90" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_us-gaap_DebtInstrumentTable_91821dba-11e5-4f11-bbdc-b65a7bfe3b90" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_4f79f956-831b-4aab-ac01-790a42cb4056" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_91821dba-11e5-4f11-bbdc-b65a7bfe3b90" xlink:to="loc_us-gaap_DebtInstrumentAxis_4f79f956-831b-4aab-ac01-790a42cb4056" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_4f79f956-831b-4aab-ac01-790a42cb4056_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_4f79f956-831b-4aab-ac01-790a42cb4056" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_4f79f956-831b-4aab-ac01-790a42cb4056_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_19e44640-aa9d-439c-9ac7-c36678737c9d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_4f79f956-831b-4aab-ac01-790a42cb4056" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_19e44640-aa9d-439c-9ac7-c36678737c9d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JulyTwoThousandTwentyFourNotesMember_185fdcd9-bffd-427c-8044-afdc16e1bd9e" xlink:href="htgc-20240630.xsd#htgc_JulyTwoThousandTwentyFourNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_19e44640-aa9d-439c-9ac7-c36678737c9d" xlink:to="loc_htgc_JulyTwoThousandTwentyFourNotesMember_185fdcd9-bffd-427c-8044-afdc16e1bd9e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_FebruaryTwoThousandTwentyFiveNotesMember_c6b2eb60-0eca-47b0-96b1-1ea622a119d7" xlink:href="htgc-20240630.xsd#htgc_FebruaryTwoThousandTwentyFiveNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_19e44640-aa9d-439c-9ac7-c36678737c9d" xlink:to="loc_htgc_FebruaryTwoThousandTwentyFiveNotesMember_c6b2eb60-0eca-47b0-96b1-1ea622a119d7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JuneTwoThousandTwentyFiveNotesMember_e792dab6-cdd7-42c9-ac67-c6f716618b8e" xlink:href="htgc-20240630.xsd#htgc_JuneTwoThousandTwentyFiveNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_19e44640-aa9d-439c-9ac7-c36678737c9d" xlink:to="loc_htgc_JuneTwoThousandTwentyFiveNotesMember_e792dab6-cdd7-42c9-ac67-c6f716618b8e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JuneTwoThousandTwentyFiveThreeYearNotesMember_bc3478dc-c2aa-4adb-ba80-785cdbb2a474" xlink:href="htgc-20240630.xsd#htgc_JuneTwoThousandTwentyFiveThreeYearNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_19e44640-aa9d-439c-9ac7-c36678737c9d" xlink:to="loc_htgc_JuneTwoThousandTwentyFiveThreeYearNotesMember_bc3478dc-c2aa-4adb-ba80-785cdbb2a474" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MarchTwoThousandTwentySixANotesMember_5b3531ac-b218-49aa-9f16-68a49dfb6352" xlink:href="htgc-20240630.xsd#htgc_MarchTwoThousandTwentySixANotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_19e44640-aa9d-439c-9ac7-c36678737c9d" xlink:to="loc_htgc_MarchTwoThousandTwentySixANotesMember_5b3531ac-b218-49aa-9f16-68a49dfb6352" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MarchTwoThousandTwentySixBNotesMember_e60b4e8d-cf11-4bf1-8563-866ea1ae3292" xlink:href="htgc-20240630.xsd#htgc_MarchTwoThousandTwentySixBNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_19e44640-aa9d-439c-9ac7-c36678737c9d" xlink:to="loc_htgc_MarchTwoThousandTwentySixBNotesMember_e60b4e8d-cf11-4bf1-8563-866ea1ae3292" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SeptemberTwoThousandTwentySixNotesMember_8ba28479-fb5a-4326-ba1a-b34fa5aacf6e" xlink:href="htgc-20240630.xsd#htgc_SeptemberTwoThousandTwentySixNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_19e44640-aa9d-439c-9ac7-c36678737c9d" xlink:to="loc_htgc_SeptemberTwoThousandTwentySixNotesMember_8ba28479-fb5a-4326-ba1a-b34fa5aacf6e" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JanuaryTwoThousandTwentySevenNotesMember_180af56c-bcf2-4787-97c1-1fb554faf50a" xlink:href="htgc-20240630.xsd#htgc_JanuaryTwoThousandTwentySevenNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_19e44640-aa9d-439c-9ac7-c36678737c9d" xlink:to="loc_htgc_JanuaryTwoThousandTwentySevenNotesMember_180af56c-bcf2-4787-97c1-1fb554faf50a" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TwoThousandThirtyOneAssetBackedNotesMember_3a2f0e03-240b-4415-8844-41b981891cb6" xlink:href="htgc-20240630.xsd#htgc_TwoThousandThirtyOneAssetBackedNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_19e44640-aa9d-439c-9ac7-c36678737c9d" xlink:to="loc_htgc_TwoThousandThirtyOneAssetBackedNotesMember_3a2f0e03-240b-4415-8844-41b981891cb6" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TwoThousandThirtyThreeNotesMember_c761f20f-50bb-45f1-ab91-810874fbec49" xlink:href="htgc-20240630.xsd#htgc_TwoThousandThirtyThreeNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_19e44640-aa9d-439c-9ac7-c36678737c9d" xlink:to="loc_htgc_TwoThousandThirtyThreeNotesMember_c761f20f-50bb-45f1-ab91-810874fbec49" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesMember_646167d1-1efa-4ab0-929c-29c4e27c0a62" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_19e44640-aa9d-439c-9ac7-c36678737c9d" xlink:to="loc_htgc_SBADebenturesMember_646167d1-1efa-4ab0-929c-29c4e27c0a62" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_343da8e4-f449-4d12-82d6-2a9c40394026" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_91821dba-11e5-4f11-bbdc-b65a7bfe3b90" xlink:to="loc_dei_LegalEntityAxis_343da8e4-f449-4d12-82d6-2a9c40394026" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_343da8e4-f449-4d12-82d6-2a9c40394026_default" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_343da8e4-f449-4d12-82d6-2a9c40394026" xlink:to="loc_dei_EntityDomain_343da8e4-f449-4d12-82d6-2a9c40394026_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_6c8a61a0-3989-4ffc-acde-dd630d45621a" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_343da8e4-f449-4d12-82d6-2a9c40394026" xlink:to="loc_dei_EntityDomain_6c8a61a0-3989-4ffc-acde-dd630d45621a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_HerculesCapitalFourLPMember_788228cc-dbcf-4776-a00a-5ff92234b45c" xlink:href="htgc-20240630.xsd#htgc_HerculesCapitalFourLPMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_6c8a61a0-3989-4ffc-acde-dd630d45621a" xlink:to="loc_htgc_HerculesCapitalFourLPMember_788228cc-dbcf-4776-a00a-5ff92234b45c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_4e9aaddb-ee2c-4c3b-b2ae-9d750155f052" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_91821dba-11e5-4f11-bbdc-b65a7bfe3b90" xlink:to="loc_srt_ConsolidatedEntitiesAxis_4e9aaddb-ee2c-4c3b-b2ae-9d750155f052" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_4e9aaddb-ee2c-4c3b-b2ae-9d750155f052_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_4e9aaddb-ee2c-4c3b-b2ae-9d750155f052" xlink:to="loc_srt_ConsolidatedEntitiesDomain_4e9aaddb-ee2c-4c3b-b2ae-9d750155f052_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_2218eb95-74e2-4507-9b78-81e3ba8cfc5a" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_4e9aaddb-ee2c-4c3b-b2ae-9d750155f052" xlink:to="loc_srt_ConsolidatedEntitiesDomain_2218eb95-74e2-4507-9b78-81e3ba8cfc5a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_88eb2d78-492a-4215-98c8-523805c1dbaa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_VariableInterestEntityPrimaryBeneficiaryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_2218eb95-74e2-4507-9b78-81e3ba8cfc5a" xlink:to="loc_us-gaap_VariableInterestEntityPrimaryBeneficiaryMember_88eb2d78-492a-4215-98c8-523805c1dbaa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_12e79da5-6e04-4d2f-b58c-a7e3a13f8afe" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_91821dba-11e5-4f11-bbdc-b65a7bfe3b90" xlink:to="loc_us-gaap_CreditFacilityAxis_12e79da5-6e04-4d2f-b58c-a7e3a13f8afe" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_12e79da5-6e04-4d2f-b58c-a7e3a13f8afe_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_12e79da5-6e04-4d2f-b58c-a7e3a13f8afe" xlink:to="loc_us-gaap_CreditFacilityDomain_12e79da5-6e04-4d2f-b58c-a7e3a13f8afe_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_19167702-e537-4548-aa85-7dfdb7daca66" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_12e79da5-6e04-4d2f-b58c-a7e3a13f8afe" xlink:to="loc_us-gaap_CreditFacilityDomain_19167702-e537-4548-aa85-7dfdb7daca66" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_52b6a650-3168-402d-82f7-7fea8d9d7f82" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_19167702-e537-4548-aa85-7dfdb7daca66" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_52b6a650-3168-402d-82f7-7fea8d9d7f82" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MUFGBankFacilityMember_ce087090-6269-4aa5-91b0-d6c2517381b5" xlink:href="htgc-20240630.xsd#htgc_MUFGBankFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_19167702-e537-4548-aa85-7dfdb7daca66" xlink:to="loc_htgc_MUFGBankFacilityMember_ce087090-6269-4aa5-91b0-d6c2517381b5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SMBCFacilityMember_6ec107b8-2fc6-461a-bd92-8200ebc698fc" xlink:href="htgc-20240630.xsd#htgc_SMBCFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_19167702-e537-4548-aa85-7dfdb7daca66" xlink:to="loc_htgc_SMBCFacilityMember_6ec107b8-2fc6-461a-bd92-8200ebc698fc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SmbcLcFacilityMember_ffda1b70-5965-4d15-b8bd-9741169b07c1" xlink:href="htgc-20240630.xsd#htgc_SmbcLcFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_19167702-e537-4548-aa85-7dfdb7daca66" xlink:to="loc_htgc_SmbcLcFacilityMember_ffda1b70-5965-4d15-b8bd-9741169b07c1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_3a251e6d-db04-44c8-9882-eab60cc2971f" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_91821dba-11e5-4f11-bbdc-b65a7bfe3b90" xlink:to="loc_srt_RangeAxis_3a251e6d-db04-44c8-9882-eab60cc2971f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_3a251e6d-db04-44c8-9882-eab60cc2971f_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_3a251e6d-db04-44c8-9882-eab60cc2971f" xlink:to="loc_srt_RangeMember_3a251e6d-db04-44c8-9882-eab60cc2971f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_2df0a233-0dbf-4a5b-afee-bcc11b846c0c" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_3a251e6d-db04-44c8-9882-eab60cc2971f" xlink:to="loc_srt_RangeMember_2df0a233-0dbf-4a5b-afee-bcc11b846c0c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_a3e6c159-d5fd-4e70-8be1-387602156cec" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_2df0a233-0dbf-4a5b-afee-bcc11b846c0c" xlink:to="loc_srt_MinimumMember_a3e6c159-d5fd-4e70-8be1-387602156cec" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_d3a66751-f805-4a0f-870b-7521d666f568" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_2df0a233-0dbf-4a5b-afee-bcc11b846c0c" xlink:to="loc_srt_MaximumMember_d3a66751-f805-4a0f-870b-7521d666f568" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_463f2bd3-229c-4fcd-88e9-8c375691c4e0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_VariableRateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_91821dba-11e5-4f11-bbdc-b65a7bfe3b90" xlink:to="loc_us-gaap_VariableRateAxis_463f2bd3-229c-4fcd-88e9-8c375691c4e0" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_463f2bd3-229c-4fcd-88e9-8c375691c4e0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_463f2bd3-229c-4fcd-88e9-8c375691c4e0" xlink:to="loc_us-gaap_VariableRateDomain_463f2bd3-229c-4fcd-88e9-8c375691c4e0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_0d9bdb6a-d394-44ad-9dc0-badaeaf2d662" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_463f2bd3-229c-4fcd-88e9-8c375691c4e0" xlink:to="loc_us-gaap_VariableRateDomain_0d9bdb6a-d394-44ad-9dc0-badaeaf2d662" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_OneMonthSecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember_c9b471ac-b0e5-4a2c-86d5-cae5b15d5d6f" xlink:href="htgc-20240630.xsd#htgc_OneMonthSecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_0d9bdb6a-d394-44ad-9dc0-badaeaf2d662" xlink:to="loc_htgc_OneMonthSecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember_c9b471ac-b0e5-4a2c-86d5-cae5b15d5d6f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_da9b9352-4a63-4fe2-878d-6af808ef23c8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_91821dba-11e5-4f11-bbdc-b65a7bfe3b90" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_da9b9352-4a63-4fe2-878d-6af808ef23c8" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_da9b9352-4a63-4fe2-878d-6af808ef23c8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_da9b9352-4a63-4fe2-878d-6af808ef23c8" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_da9b9352-4a63-4fe2-878d-6af808ef23c8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_b34bc69b-3eb0-411b-9df9-1f0f9db28c6f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_da9b9352-4a63-4fe2-878d-6af808ef23c8" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_b34bc69b-3eb0-411b-9df9-1f0f9db28c6f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_d7fc1ad0-9c46-482a-ae72-544bbfd6641e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_b34bc69b-3eb0-411b-9df9-1f0f9db28c6f" xlink:to="loc_us-gaap_SubsequentEventMember_d7fc1ad0-9c46-482a-ae72-544bbfd6641e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DebtInstrumentLicenseDescription_40f0d843-0c20-4e01-88f7-9e5a17af9b53" xlink:href="htgc-20240630.xsd#htgc_DebtInstrumentLicenseDescription"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_htgc_DebtInstrumentLicenseDescription_40f0d843-0c20-4e01-88f7-9e5a17af9b53" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_LicenseTerm_299effeb-efbe-4aef-a26b-a006d11b6818" xlink:href="htgc-20240630.xsd#htgc_LicenseTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_htgc_LicenseTerm_299effeb-efbe-4aef-a26b-a006d11b6818" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_cda66b99-e47e-4d5b-af2b-b7da939fe997" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_cda66b99-e47e-4d5b-af2b-b7da939fe997" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_RegulatoryCapitalCommitmentAmount_bc8e8ae5-559e-4a89-a4be-9da2e619a6de" xlink:href="htgc-20240630.xsd#htgc_RegulatoryCapitalCommitmentAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_htgc_RegulatoryCapitalCommitmentAmount_bc8e8ae5-559e-4a89-a4be-9da2e619a6de" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_81bcec28-89c0-4689-bcfb-159fd60bf940" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_81bcec28-89c0-4689-bcfb-159fd60bf940" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_InvestmentsHeldByNumberOfCompanies_8da28cd7-c05d-4546-a21a-991857aaf6bb" xlink:href="htgc-20240630.xsd#htgc_InvestmentsHeldByNumberOfCompanies"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_htgc_InvestmentsHeldByNumberOfCompanies_8da28cd7-c05d-4546-a21a-991857aaf6bb" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtFairValue_86cba635-2c6a-4b49-9159-4a149302211a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_us-gaap_InvestmentOwnedAtFairValue_86cba635-2c6a-4b49-9159-4a149302211a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_PercentageOfInvestmentPortfolio_95a37849-6e1c-40f4-9c78-e3b62d5d3620" xlink:href="htgc-20240630.xsd#htgc_PercentageOfInvestmentPortfolio"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_htgc_PercentageOfInvestmentPortfolio_95a37849-6e1c-40f4-9c78-e3b62d5d3620" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TangibleAssets_95d38312-e145-4f12-aeb7-db1c4ba50a5e" xlink:href="htgc-20240630.xsd#htgc_TangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_htgc_TangibleAssets_95d38312-e145-4f12-aeb7-db1c4ba50a5e" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_PercentageOfAssetsHeld_22713157-06cf-41ea-94eb-39988044492e" xlink:href="htgc-20240630.xsd#htgc_PercentageOfAssetsHeld"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_htgc_PercentageOfAssetsHeld_22713157-06cf-41ea-94eb-39988044492e" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_8ac89eca-6cd3-46d7-814e-3b148ff3e9b2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_us-gaap_LongTermDebt_8ac89eca-6cd3-46d7-814e-3b148ff3e9b2" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBICLicenseTerm_eaee746e-782c-42ec-a99b-f69ae799a7fb" xlink:href="htgc-20240630.xsd#htgc_SBICLicenseTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_htgc_SBICLicenseTerm_eaee746e-782c-42ec-a99b-f69ae799a7fb" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_05c88f76-4db2-44c4-b8d9-8999955ed02f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_05c88f76-4db2-44c4-b8d9-8999955ed02f" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentMaturityDate_549fa9f2-5fb3-4d3d-a0ea-8f6b45af07a4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentMaturityDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_us-gaap_DebtInstrumentMaturityDate_549fa9f2-5fb3-4d3d-a0ea-8f6b45af07a4" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionDescription_323194c3-c4d8-44cf-8fd7-538fdabea620" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRedemptionDescription"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_us-gaap_DebtInstrumentRedemptionDescription_323194c3-c4d8-44cf-8fd7-538fdabea620" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentPaymentTerms_72182026-9572-43ed-8165-47d2ddc8b274" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentPaymentTerms"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_us-gaap_DebtInstrumentPaymentTerms_72182026-9572-43ed-8165-47d2ddc8b274" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCollateral_30ac50b0-4615-4799-94d3-2a84d5d7b1c8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentCollateral"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_us-gaap_DebtInstrumentCollateral_30ac50b0-4615-4799-94d3-2a84d5d7b1c8" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfDebt_89009c9f-8357-4854-b1e3-efb91edbe993" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RepaymentsOfDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_us-gaap_RepaymentsOfDebt_89009c9f-8357-4854-b1e3-efb91edbe993" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_RepaymentOfAccruedInterest_f78f9352-040b-44b0-b494-cbab83dfed02" xlink:href="htgc-20240630.xsd#htgc_RepaymentOfAccruedInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_htgc_RepaymentOfAccruedInterest_f78f9352-040b-44b0-b494-cbab83dfed02" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCash_5a343874-23f1-425f-9b52-ff79b298f9e1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestrictedCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_us-gaap_RestrictedCash_5a343874-23f1-425f-9b52-ff79b298f9e1" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_NumberOfAvailableCreditFacilities_6d9099c2-561d-447a-8690-950890896528" xlink:href="htgc-20240630.xsd#htgc_NumberOfAvailableCreditFacilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_htgc_NumberOfAvailableCreditFacilities_6d9099c2-561d-447a-8690-950890896528" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityInterestRateDuringPeriod_54bbfc38-539d-4e57-8f3c-eacebfed0c56" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCreditFacilityInterestRateDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_us-gaap_LineOfCreditFacilityInterestRateDuringPeriod_54bbfc38-539d-4e57-8f3c-eacebfed0c56" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityAverageOutstandingAmount_50143b6e-dc00-4038-a898-196ba5db65e0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCreditFacilityAverageOutstandingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_us-gaap_LineOfCreditFacilityAverageOutstandingAmount_50143b6e-dc00-4038-a898-196ba5db65e0" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityDescription_5061d085-e84a-4035-94b1-cd3c714f70e9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCreditFacilityDescription"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_us-gaap_LineOfCreditFacilityDescription_5061d085-e84a-4035-94b1-cd3c714f70e9" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentVariableInterestRateTypeExtensibleEnumeration_f1964552-b9cc-4230-89b4-097690c2709d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentVariableInterestRateTypeExtensibleEnumeration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_us-gaap_DebtInstrumentVariableInterestRateTypeExtensibleEnumeration_f1964552-b9cc-4230-89b4-097690c2709d" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_87523754-233c-46f9-86f0-18191d3f4350" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_87523754-233c-46f9-86f0-18191d3f4350" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityCovenantTerms_686d3256-92c3-469d-9c29-6ac9faa84d61" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCreditFacilityCovenantTerms"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_us-gaap_LineOfCreditFacilityCovenantTerms_686d3256-92c3-469d-9c29-6ac9faa84d61" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_a0636925-26f3-4721-8d99-972a61d0988a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_3bc89b78-eca3-4f33-a782-b71584a8a17e" xlink:to="loc_us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage_a0636925-26f3-4721-8d99-972a61d0988a" xlink:type="arc" order="27"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/IncomeTaxesNarrativeDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#IncomeTaxesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/IncomeTaxesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowanceLineItems_55a6b4d1-6f43-4178-8810-da693c022b06" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ValuationAllowanceLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowanceTable_7318638b-f12f-4970-85ff-bb1694f548ae" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ValuationAllowanceTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ValuationAllowanceLineItems_55a6b4d1-6f43-4178-8810-da693c022b06" xlink:to="loc_us-gaap_ValuationAllowanceTable_7318638b-f12f-4970-85ff-bb1694f548ae" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeAxis_543747dd-9ae1-4dea-b24c-06985d2e4214" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ValuationAllowanceTable_7318638b-f12f-4970-85ff-bb1694f548ae" xlink:to="loc_us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeAxis_543747dd-9ae1-4dea-b24c-06985d2e4214" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeDomain_543747dd-9ae1-4dea-b24c-06985d2e4214_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeAxis_543747dd-9ae1-4dea-b24c-06985d2e4214" xlink:to="loc_us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeDomain_543747dd-9ae1-4dea-b24c-06985d2e4214_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeDomain_568533f2-8d96-45b4-91e4-4867b86cec02" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeAxis_543747dd-9ae1-4dea-b24c-06985d2e4214" xlink:to="loc_us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeDomain_568533f2-8d96-45b4-91e4-4867b86cec02" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeOrGroupOfInvesteesMember_db1d3fd5-4ebf-44ba-9916-aab7515cd9f3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeOrGroupOfInvesteesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeDomain_568533f2-8d96-45b4-91e4-4867b86cec02" xlink:to="loc_us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeOrGroupOfInvesteesMember_db1d3fd5-4ebf-44ba-9916-aab7515cd9f3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalOther_b3e4a3f9-b439-4293-8063-f296220b22cf" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowanceLineItems_55a6b4d1-6f43-4178-8810-da693c022b06" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalOther_b3e4a3f9-b439-4293-8063-f296220b22cf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxesPaidNet_56d29b4b-2a41-4ec6-925b-09509728855c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxesPaidNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowanceLineItems_55a6b4d1-6f43-4178-8810-da693c022b06" xlink:to="loc_us-gaap_IncomeTaxesPaidNet_56d29b4b-2a41-4ec6-925b-09509728855c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxesPayableCurrentAndNoncurrent_a4cb916f-53dc-4152-88ac-a86df49ffb5c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TaxesPayableCurrentAndNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowanceLineItems_55a6b4d1-6f43-4178-8810-da693c022b06" xlink:to="loc_us-gaap_TaxesPayableCurrentAndNoncurrent_a4cb916f-53dc-4152-88ac-a86df49ffb5c" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/StockholdersEquityandDistributionsNarrativeDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#StockholdersEquityandDistributionsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/StockholdersEquityandDistributionsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_79f6122e-4be7-4b3f-9bcf-53ecfa194f72" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_5b140940-164b-4d55-8b9e-0e1f487e0a8f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_79f6122e-4be7-4b3f-9bcf-53ecfa194f72" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_5b140940-164b-4d55-8b9e-0e1f487e0a8f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_d84e2991-8c2c-4070-81da-826f5f66e3ec" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_5b140940-164b-4d55-8b9e-0e1f487e0a8f" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_d84e2991-8c2c-4070-81da-826f5f66e3ec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_d84e2991-8c2c-4070-81da-826f5f66e3ec_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_d84e2991-8c2c-4070-81da-826f5f66e3ec" xlink:to="loc_us-gaap_EquityComponentDomain_d84e2991-8c2c-4070-81da-826f5f66e3ec_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_c9313767-7b44-4a84-8066-43e70cba661e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_d84e2991-8c2c-4070-81da-826f5f66e3ec" xlink:to="loc_us-gaap_EquityComponentDomain_c9313767-7b44-4a84-8066-43e70cba661e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_c475e051-e480-4a32-959d-b12ed6782e68" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_c9313767-7b44-4a84-8066-43e70cba661e" xlink:to="loc_us-gaap_CommonStockMember_c475e051-e480-4a32-959d-b12ed6782e68" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TypeOfArrangementAxis_2268bfb5-d769-4ed6-8475-82488fe0bf9f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TypeOfArrangementAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_5b140940-164b-4d55-8b9e-0e1f487e0a8f" xlink:to="loc_us-gaap_TypeOfArrangementAxis_2268bfb5-d769-4ed6-8475-82488fe0bf9f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_2268bfb5-d769-4ed6-8475-82488fe0bf9f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TypeOfArrangementAxis_2268bfb5-d769-4ed6-8475-82488fe0bf9f" xlink:to="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_2268bfb5-d769-4ed6-8475-82488fe0bf9f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_12f06dc5-ca74-4e57-be96-80d7540f737e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TypeOfArrangementAxis_2268bfb5-d769-4ed6-8475-82488fe0bf9f" xlink:to="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_12f06dc5-ca74-4e57-be96-80d7540f737e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TwoThousandTwentyThreeEquityDistributionAgreementMember_caea0c1b-bf78-46e5-b732-db8dfa4a890f" xlink:href="htgc-20240630.xsd#htgc_TwoThousandTwentyThreeEquityDistributionAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ArrangementsAndNonarrangementTransactionsMember_12f06dc5-ca74-4e57-be96-80d7540f737e" xlink:to="loc_htgc_TwoThousandTwentyThreeEquityDistributionAgreementMember_caea0c1b-bf78-46e5-b732-db8dfa4a890f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_05a15707-d2c2-4f61-aaf3-acd015129a84" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_5b140940-164b-4d55-8b9e-0e1f487e0a8f" xlink:to="loc_us-gaap_StatementClassOfStockAxis_05a15707-d2c2-4f61-aaf3-acd015129a84" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_05a15707-d2c2-4f61-aaf3-acd015129a84_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_05a15707-d2c2-4f61-aaf3-acd015129a84" xlink:to="loc_us-gaap_ClassOfStockDomain_05a15707-d2c2-4f61-aaf3-acd015129a84_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_8c0017d9-5064-4062-8244-632c2af4fbf4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_05a15707-d2c2-4f61-aaf3-acd015129a84" xlink:to="loc_us-gaap_ClassOfStockDomain_8c0017d9-5064-4062-8244-632c2af4fbf4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SpilloveramountpershareMember_bc683734-6c67-44a2-9371-2d01048b7cc7" xlink:href="htgc-20240630.xsd#htgc_SpilloveramountpershareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_8c0017d9-5064-4062-8244-632c2af4fbf4" xlink:to="loc_htgc_SpilloveramountpershareMember_bc683734-6c67-44a2-9371-2d01048b7cc7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_cdd2cae6-4b15-445f-8f1a-fbe77e7d4f5d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_79f6122e-4be7-4b3f-9bcf-53ecfa194f72" xlink:to="loc_us-gaap_CommonStockSharesIssued_cdd2cae6-4b15-445f-8f1a-fbe77e7d4f5d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_53c6cb17-7b99-4f4f-9ae0-33a1828bcd7c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_79f6122e-4be7-4b3f-9bcf-53ecfa194f72" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_53c6cb17-7b99-4f4f-9ae0-33a1828bcd7c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_EquityDistributionsAgreementAvailableShares_94b31575-568c-42d0-8905-97004fa163b7" xlink:href="htgc-20240630.xsd#htgc_EquityDistributionsAgreementAvailableShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_79f6122e-4be7-4b3f-9bcf-53ecfa194f72" xlink:to="loc_htgc_EquityDistributionsAgreementAvailableShares_94b31575-568c-42d0-8905-97004fa163b7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_EquityDistributionAgreementRemainingAvailableShares_ab73a007-a26e-43a1-90a3-22bbc4b90654" xlink:href="htgc-20240630.xsd#htgc_EquityDistributionAgreementRemainingAvailableShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_79f6122e-4be7-4b3f-9bcf-53ecfa194f72" xlink:to="loc_htgc_EquityDistributionAgreementRemainingAvailableShares_ab73a007-a26e-43a1-90a3-22bbc4b90654" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyDistributionToShareholdersPerShare_87d12f88-e240-412b-8369-b11f9c72b8ee" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentCompanyDistributionToShareholdersPerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_79f6122e-4be7-4b3f-9bcf-53ecfa194f72" xlink:to="loc_us-gaap_InvestmentCompanyDistributionToShareholdersPerShare_87d12f88-e240-412b-8369-b11f9c72b8ee" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_UndistributedTaxableEarnings_4179d35d-110f-4b73-b832-ed6c33682e50" xlink:href="htgc-20240630.xsd#htgc_UndistributedTaxableEarnings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_79f6122e-4be7-4b3f-9bcf-53ecfa194f72" xlink:to="loc_htgc_UndistributedTaxableEarnings_4179d35d-110f-4b73-b832-ed6c33682e50" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan_e05e1bc9-4109-414a-bf65-fc06fcc68bb1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_79f6122e-4be7-4b3f-9bcf-53ecfa194f72" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesDividendReinvestmentPlan_e05e1bc9-4109-414a-bf65-fc06fcc68bb1" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/StockholdersEquityandDistributionsScheduleofCommonStockSharesIssuedandSoldDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#StockholdersEquityandDistributionsScheduleofCommonStockSharesIssuedandSoldDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/StockholdersEquityandDistributionsScheduleofCommonStockSharesIssuedandSoldDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_6aaa309e-d031-4429-8f2d-4990b122cea0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_916eebf9-663b-4b2f-8a59-438cc4d97663" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_6aaa309e-d031-4429-8f2d-4990b122cea0" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_916eebf9-663b-4b2f-8a59-438cc4d97663" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_52638f4f-6380-4a1b-b8ad-46f18a507823" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_916eebf9-663b-4b2f-8a59-438cc4d97663" xlink:to="loc_us-gaap_StatementClassOfStockAxis_52638f4f-6380-4a1b-b8ad-46f18a507823" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_52638f4f-6380-4a1b-b8ad-46f18a507823_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_52638f4f-6380-4a1b-b8ad-46f18a507823" xlink:to="loc_us-gaap_ClassOfStockDomain_52638f4f-6380-4a1b-b8ad-46f18a507823_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_1bdf2c63-8201-44e6-ab84-4aef6130703b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_52638f4f-6380-4a1b-b8ad-46f18a507823" xlink:to="loc_us-gaap_ClassOfStockDomain_1bdf2c63-8201-44e6-ab84-4aef6130703b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CommonGrossProceedsMember_ed49717d-2b59-4144-ab82-f1885921009e" xlink:href="htgc-20240630.xsd#htgc_CommonGrossProceedsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_1bdf2c63-8201-44e6-ab84-4aef6130703b" xlink:to="loc_htgc_CommonGrossProceedsMember_ed49717d-2b59-4144-ab82-f1885921009e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CommonOfferingExpensesMember_1c95bde2-704e-415f-bee2-7e7edc5b21ac" xlink:href="htgc-20240630.xsd#htgc_CommonOfferingExpensesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_1bdf2c63-8201-44e6-ab84-4aef6130703b" xlink:to="loc_htgc_CommonOfferingExpensesMember_1c95bde2-704e-415f-bee2-7e7edc5b21ac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_bc290bba-ffe0-429f-a51c-1d2910f051ab" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_6aaa309e-d031-4429-8f2d-4990b122cea0" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_bc290bba-ffe0-429f-a51c-1d2910f051ab" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_56aec737-94bf-4749-a2c0-df2997aec5e2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_6aaa309e-d031-4429-8f2d-4990b122cea0" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_56aec737-94bf-4749-a2c0-df2997aec5e2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesIssuedPricePerShare_05d51624-88cd-4458-90fc-ea615b80fea8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharesIssuedPricePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_6aaa309e-d031-4429-8f2d-4990b122cea0" xlink:to="loc_us-gaap_SharesIssuedPricePerShare_05d51624-88cd-4458-90fc-ea615b80fea8" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/StockholdersEquityandDistributionsScheduleofDividendsDeclaredDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#StockholdersEquityandDistributionsScheduleofDividendsDeclaredDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/StockholdersEquityandDistributionsScheduleofDividendsDeclaredDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPayableLineItems_100b0542-6a3a-4f8c-bed1-9b6c428a4f02" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsPayableLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPayableTable_b2a3ac19-2000-4395-b81d-c8b161d8b369" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsPayableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DividendsPayableLineItems_100b0542-6a3a-4f8c-bed1-9b6c428a4f02" xlink:to="loc_us-gaap_DividendsPayableTable_b2a3ac19-2000-4395-b81d-c8b161d8b369" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsAxis_b610a2e8-3ddb-43b6-84a8-1fb3b8b22175" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DividendsPayableTable_b2a3ac19-2000-4395-b81d-c8b161d8b369" xlink:to="loc_us-gaap_DividendsAxis_b610a2e8-3ddb-43b6-84a8-1fb3b8b22175" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsDomain_b610a2e8-3ddb-43b6-84a8-1fb3b8b22175_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DividendsAxis_b610a2e8-3ddb-43b6-84a8-1fb3b8b22175" xlink:to="loc_us-gaap_DividendsDomain_b610a2e8-3ddb-43b6-84a8-1fb3b8b22175_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsDomain_9f5faa2a-9a77-4d7d-b775-d29a675c23ff" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DividendsAxis_b610a2e8-3ddb-43b6-84a8-1fb3b8b22175" xlink:to="loc_us-gaap_DividendsDomain_9f5faa2a-9a77-4d7d-b775-d29a675c23ff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DividendDeclaredOneMember_dc949aa6-7fdf-4d9b-9bec-81031b8fc3f4" xlink:href="htgc-20240630.xsd#htgc_DividendDeclaredOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DividendsDomain_9f5faa2a-9a77-4d7d-b775-d29a675c23ff" xlink:to="loc_htgc_DividendDeclaredOneMember_dc949aa6-7fdf-4d9b-9bec-81031b8fc3f4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DividendDeclaredTwoMember_fd266fc8-35e4-44ef-8c8c-4442c2b607b1" xlink:href="htgc-20240630.xsd#htgc_DividendDeclaredTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DividendsDomain_9f5faa2a-9a77-4d7d-b775-d29a675c23ff" xlink:to="loc_htgc_DividendDeclaredTwoMember_fd266fc8-35e4-44ef-8c8c-4442c2b607b1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DividendDeclaredThreeMember_ddeaf122-e8b3-4d1b-ae7a-733193fa9829" xlink:href="htgc-20240630.xsd#htgc_DividendDeclaredThreeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DividendsDomain_9f5faa2a-9a77-4d7d-b775-d29a675c23ff" xlink:to="loc_htgc_DividendDeclaredThreeMember_ddeaf122-e8b3-4d1b-ae7a-733193fa9829" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DividendDeclaredFourMember_2e6a61b4-01f2-42c7-a7f2-b7d6d08b3cc2" xlink:href="htgc-20240630.xsd#htgc_DividendDeclaredFourMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DividendsDomain_9f5faa2a-9a77-4d7d-b775-d29a675c23ff" xlink:to="loc_htgc_DividendDeclaredFourMember_2e6a61b4-01f2-42c7-a7f2-b7d6d08b3cc2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DividendDeclaredFiveMember_7c9c2eaa-cd71-4640-98ad-5c9d8aa885a5" xlink:href="htgc-20240630.xsd#htgc_DividendDeclaredFiveMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DividendsDomain_9f5faa2a-9a77-4d7d-b775-d29a675c23ff" xlink:to="loc_htgc_DividendDeclaredFiveMember_7c9c2eaa-cd71-4640-98ad-5c9d8aa885a5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DividendDeclaredSixMember_24a243b1-246d-4b8f-95cb-bf746923b8b9" xlink:href="htgc-20240630.xsd#htgc_DividendDeclaredSixMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DividendsDomain_9f5faa2a-9a77-4d7d-b775-d29a675c23ff" xlink:to="loc_htgc_DividendDeclaredSixMember_24a243b1-246d-4b8f-95cb-bf746923b8b9" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DividendDeclaredSevenMember_0059f003-97ba-43b0-9820-24e43b37cb8d" xlink:href="htgc-20240630.xsd#htgc_DividendDeclaredSevenMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DividendsDomain_9f5faa2a-9a77-4d7d-b775-d29a675c23ff" xlink:to="loc_htgc_DividendDeclaredSevenMember_0059f003-97ba-43b0-9820-24e43b37cb8d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DividendDeclaredEightMember_f8b3d6ac-c861-45b3-98e5-12b9a87becc6" xlink:href="htgc-20240630.xsd#htgc_DividendDeclaredEightMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DividendsDomain_9f5faa2a-9a77-4d7d-b775-d29a675c23ff" xlink:to="loc_htgc_DividendDeclaredEightMember_f8b3d6ac-c861-45b3-98e5-12b9a87becc6" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPayableNature_248fbc73-8d2a-4353-9285-dd9c278572d4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsPayableNature"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DividendsPayableLineItems_100b0542-6a3a-4f8c-bed1-9b6c428a4f02" xlink:to="loc_us-gaap_DividendsPayableNature_248fbc73-8d2a-4353-9285-dd9c278572d4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPayableDateDeclaredDayMonthAndYear_971caba0-9d97-4860-a25d-7f3e8419b078" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsPayableDateDeclaredDayMonthAndYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DividendsPayableLineItems_100b0542-6a3a-4f8c-bed1-9b6c428a4f02" xlink:to="loc_us-gaap_DividendsPayableDateDeclaredDayMonthAndYear_971caba0-9d97-4860-a25d-7f3e8419b078" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPayableDateOfRecordDayMonthAndYear_476eb12c-717b-46c7-9a0b-8550b0e4fc12" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsPayableDateOfRecordDayMonthAndYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DividendsPayableLineItems_100b0542-6a3a-4f8c-bed1-9b6c428a4f02" xlink:to="loc_us-gaap_DividendsPayableDateOfRecordDayMonthAndYear_476eb12c-717b-46c7-9a0b-8550b0e4fc12" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendPayableDateToBePaidDayMonthAndYear_2289c1a5-6242-49f0-93ac-d01327778c52" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendPayableDateToBePaidDayMonthAndYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DividendsPayableLineItems_100b0542-6a3a-4f8c-bed1-9b6c428a4f02" xlink:to="loc_us-gaap_DividendPayableDateToBePaidDayMonthAndYear_2289c1a5-6242-49f0-93ac-d01327778c52" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyDistributionToShareholdersPerShare_6b7522c3-ca7c-4a0a-9312-66c180f354b8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentCompanyDistributionToShareholdersPerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DividendsPayableLineItems_100b0542-6a3a-4f8c-bed1-9b6c428a4f02" xlink:to="loc_us-gaap_InvestmentCompanyDistributionToShareholdersPerShare_6b7522c3-ca7c-4a0a-9312-66c180f354b8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyDividendDistribution_494e9255-5bde-4e95-936d-717efddfa739" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentCompanyDividendDistribution"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DividendsPayableLineItems_100b0542-6a3a-4f8c-bed1-9b6c428a4f02" xlink:to="loc_us-gaap_InvestmentCompanyDividendDistribution_494e9255-5bde-4e95-936d-717efddfa739" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/EquityIncentivePlansNarrativeDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#EquityIncentivePlansNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/EquityIncentivePlansNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_81191b3d-5665-4ed3-9f8e-0c3879a12a5a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_2a242cfc-60ca-4a6d-8271-eaf4c6ead37c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_81191b3d-5665-4ed3-9f8e-0c3879a12a5a" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_2a242cfc-60ca-4a6d-8271-eaf4c6ead37c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_67f30783-e739-4bcf-aa28-624900eb75f7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_2a242cfc-60ca-4a6d-8271-eaf4c6ead37c" xlink:to="loc_us-gaap_PlanNameAxis_67f30783-e739-4bcf-aa28-624900eb75f7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_67f30783-e739-4bcf-aa28-624900eb75f7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_67f30783-e739-4bcf-aa28-624900eb75f7" xlink:to="loc_us-gaap_PlanNameDomain_67f30783-e739-4bcf-aa28-624900eb75f7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_92a9ffdf-64f3-4a27-9063-986fee3341fb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_67f30783-e739-4bcf-aa28-624900eb75f7" xlink:to="loc_us-gaap_PlanNameDomain_92a9ffdf-64f3-4a27-9063-986fee3341fb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TwoThousandEighteenPlanMember_8f8f37a0-5816-4eb2-bb38-a59841e5550a" xlink:href="htgc-20240630.xsd#htgc_TwoThousandEighteenPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_92a9ffdf-64f3-4a27-9063-986fee3341fb" xlink:to="loc_htgc_TwoThousandEighteenPlanMember_8f8f37a0-5816-4eb2-bb38-a59841e5550a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DirectorPlanMember_21c35f51-47e6-4a7d-af3c-86ac898274fc" xlink:href="htgc-20240630.xsd#htgc_DirectorPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_92a9ffdf-64f3-4a27-9063-986fee3341fb" xlink:to="loc_htgc_DirectorPlanMember_21c35f51-47e6-4a7d-af3c-86ac898274fc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_e71a7c4c-e33a-40bc-b359-5658b70ddac2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_2a242cfc-60ca-4a6d-8271-eaf4c6ead37c" xlink:to="loc_us-gaap_AwardTypeAxis_e71a7c4c-e33a-40bc-b359-5658b70ddac2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_e71a7c4c-e33a-40bc-b359-5658b70ddac2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_e71a7c4c-e33a-40bc-b359-5658b70ddac2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_e71a7c4c-e33a-40bc-b359-5658b70ddac2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_20d4a362-7cfa-46a3-86a6-ca42bcd5c03f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_e71a7c4c-e33a-40bc-b359-5658b70ddac2" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_20d4a362-7cfa-46a3-86a6-ca42bcd5c03f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_622b9e19-3a99-475a-9528-d210ceaba408" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_20d4a362-7cfa-46a3-86a6-ca42bcd5c03f" xlink:to="loc_us-gaap_CommonStockMember_622b9e19-3a99-475a-9528-d210ceaba408" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ServiceVestingAwardsMember_1fc7a0f8-69ff-4375-bf7c-50386750ca65" xlink:href="htgc-20240630.xsd#htgc_ServiceVestingAwardsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_20d4a362-7cfa-46a3-86a6-ca42bcd5c03f" xlink:to="loc_htgc_ServiceVestingAwardsMember_1fc7a0f8-69ff-4375-bf7c-50386750ca65" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_PerformanceVestingAwardsMember_7e57693a-eb95-43e0-bf00-1a2776d16dfc" xlink:href="htgc-20240630.xsd#htgc_PerformanceVestingAwardsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_20d4a362-7cfa-46a3-86a6-ca42bcd5c03f" xlink:to="loc_htgc_PerformanceVestingAwardsMember_7e57693a-eb95-43e0-bf00-1a2776d16dfc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_PerformanceDeuMember_128cb6c6-d87a-4686-9692-ae4318b7af37" xlink:href="htgc-20240630.xsd#htgc_PerformanceDeuMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_20d4a362-7cfa-46a3-86a6-ca42bcd5c03f" xlink:to="loc_htgc_PerformanceDeuMember_128cb6c6-d87a-4686-9692-ae4318b7af37" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_LiabilityClassifiedAwardsMember_5974b4aa-37ea-415b-aeb0-486fb8316677" xlink:href="htgc-20240630.xsd#htgc_LiabilityClassifiedAwardsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_20d4a362-7cfa-46a3-86a6-ca42bcd5c03f" xlink:to="loc_htgc_LiabilityClassifiedAwardsMember_5974b4aa-37ea-415b-aeb0-486fb8316677" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_OtherLiabilityClassifiedAwardsMember_bebef7e2-0466-4147-bf95-3548415e5a56" xlink:href="htgc-20240630.xsd#htgc_OtherLiabilityClassifiedAwardsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_20d4a362-7cfa-46a3-86a6-ca42bcd5c03f" xlink:to="loc_htgc_OtherLiabilityClassifiedAwardsMember_bebef7e2-0466-4147-bf95-3548415e5a56" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityTypeAxis_4ec755cd-b493-40c8-97b7-cd5ccd7159c9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OptionIndexedToIssuersEquityTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_2a242cfc-60ca-4a6d-8271-eaf4c6ead37c" xlink:to="loc_us-gaap_OptionIndexedToIssuersEquityTypeAxis_4ec755cd-b493-40c8-97b7-cd5ccd7159c9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_4ec755cd-b493-40c8-97b7-cd5ccd7159c9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OptionIndexedToIssuersEquityTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_OptionIndexedToIssuersEquityTypeAxis_4ec755cd-b493-40c8-97b7-cd5ccd7159c9" xlink:to="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_4ec755cd-b493-40c8-97b7-cd5ccd7159c9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_a639fe11-f7ba-4858-a6e4-6f7b4b160724" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OptionIndexedToIssuersEquityTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_OptionIndexedToIssuersEquityTypeAxis_4ec755cd-b493-40c8-97b7-cd5ccd7159c9" xlink:to="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_a639fe11-f7ba-4858-a6e4-6f7b4b160724" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_76757bfc-2aa2-431a-99f7-a796e97355b7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OptionIndexedToIssuersEquityTypeDomain_a639fe11-f7ba-4858-a6e4-6f7b4b160724" xlink:to="loc_us-gaap_EmployeeStockOptionMember_76757bfc-2aa2-431a-99f7-a796e97355b7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_74d2cdc3-9728-4b30-8217-bc2fe5a0d219" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_2a242cfc-60ca-4a6d-8271-eaf4c6ead37c" xlink:to="loc_srt_RangeAxis_74d2cdc3-9728-4b30-8217-bc2fe5a0d219" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_74d2cdc3-9728-4b30-8217-bc2fe5a0d219_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_74d2cdc3-9728-4b30-8217-bc2fe5a0d219" xlink:to="loc_srt_RangeMember_74d2cdc3-9728-4b30-8217-bc2fe5a0d219_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_13675dd0-fe29-4c6c-a8ce-cf24bb89e7a4" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_74d2cdc3-9728-4b30-8217-bc2fe5a0d219" xlink:to="loc_srt_RangeMember_13675dd0-fe29-4c6c-a8ce-cf24bb89e7a4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_3263a184-55c4-4f20-b4d9-e2376b6c952d" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_13675dd0-fe29-4c6c-a8ce-cf24bb89e7a4" xlink:to="loc_srt_MinimumMember_3263a184-55c4-4f20-b4d9-e2376b6c952d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_d340a95a-e455-4e4e-a092-549d0e385910" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_13675dd0-fe29-4c6c-a8ce-cf24bb89e7a4" xlink:to="loc_srt_MaximumMember_d340a95a-e455-4e4e-a092-549d0e385910" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingAxis_eafb60da-7a19-4bb2-9028-eff033e81c9d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_VestingAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_2a242cfc-60ca-4a6d-8271-eaf4c6ead37c" xlink:to="loc_us-gaap_VestingAxis_eafb60da-7a19-4bb2-9028-eff033e81c9d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingDomain_eafb60da-7a19-4bb2-9028-eff033e81c9d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_VestingDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VestingAxis_eafb60da-7a19-4bb2-9028-eff033e81c9d" xlink:to="loc_us-gaap_VestingDomain_eafb60da-7a19-4bb2-9028-eff033e81c9d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingDomain_2f29edab-e5ec-4e75-ba65-856479a80a08" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_VestingDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VestingAxis_eafb60da-7a19-4bb2-9028-eff033e81c9d" xlink:to="loc_us-gaap_VestingDomain_2f29edab-e5ec-4e75-ba65-856479a80a08" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheOneMember_0ea13352-ebb8-4e6e-b389-c4ab071d4581" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationAwardTrancheOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VestingDomain_2f29edab-e5ec-4e75-ba65-856479a80a08" xlink:to="loc_us-gaap_ShareBasedCompensationAwardTrancheOneMember_0ea13352-ebb8-4e6e-b389-c4ab071d4581" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ShareBasedPaymentArrangementTrancheTwoAndThreeMember_c08c4e35-7368-4752-9562-e9ff71b215de" xlink:href="htgc-20240630.xsd#htgc_ShareBasedPaymentArrangementTrancheTwoAndThreeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VestingDomain_2f29edab-e5ec-4e75-ba65-856479a80a08" xlink:to="loc_htgc_ShareBasedPaymentArrangementTrancheTwoAndThreeMember_c08c4e35-7368-4752-9562-e9ff71b215de" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheTwoMember_0f928d18-4c64-4bb2-bf97-7231a810bb1d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationAwardTrancheTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_ShareBasedPaymentArrangementTrancheTwoAndThreeMember_c08c4e35-7368-4752-9562-e9ff71b215de" xlink:to="loc_us-gaap_ShareBasedCompensationAwardTrancheTwoMember_0f928d18-4c64-4bb2-bf97-7231a810bb1d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheThreeMember_c58aa52d-49f4-49ef-9b5f-a948e7e1e072" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationAwardTrancheThreeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_ShareBasedPaymentArrangementTrancheTwoAndThreeMember_c08c4e35-7368-4752-9562-e9ff71b215de" xlink:to="loc_us-gaap_ShareBasedCompensationAwardTrancheThreeMember_c58aa52d-49f4-49ef-9b5f-a948e7e1e072" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredCompensationArrangementWithIndividualSharesAuthorizedForIssuance_a17d854c-f17b-482b-bfcd-5fe7b2a0068b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredCompensationArrangementWithIndividualSharesAuthorizedForIssuance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_81191b3d-5665-4ed3-9f8e-0c3879a12a5a" xlink:to="loc_us-gaap_DeferredCompensationArrangementWithIndividualSharesAuthorizedForIssuance_a17d854c-f17b-482b-bfcd-5fe7b2a0068b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_faa5a1b0-7ebf-4780-815d-58ba70ffe7c6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_81191b3d-5665-4ed3-9f8e-0c3879a12a5a" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_faa5a1b0-7ebf-4780-815d-58ba70ffe7c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_ca59de57-120d-41b6-89de-3049d7674a51" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_81191b3d-5665-4ed3-9f8e-0c3879a12a5a" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_ca59de57-120d-41b6-89de-3049d7674a51" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_6fa857f1-bc8e-47cd-8f07-4b0b34b73a7c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_81191b3d-5665-4ed3-9f8e-0c3879a12a5a" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_6fa857f1-bc8e-47cd-8f07-4b0b34b73a7c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardTermsOfAward_a59010a0-3580-4be8-84de-0007f996307d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardTermsOfAward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_81191b3d-5665-4ed3-9f8e-0c3879a12a5a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardTermsOfAward_a59010a0-3580-4be8-84de-0007f996307d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_8b4caa2a-bfff-40e9-9d38-5f5a9875b894" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_81191b3d-5665-4ed3-9f8e-0c3879a12a5a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_8b4caa2a-bfff-40e9-9d38-5f5a9875b894" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ShareBasedCompensationAggregateIntrinsicValueGranted_4cfda828-1ac0-4026-99cf-a27d2a44aa47" xlink:href="htgc-20240630.xsd#htgc_ShareBasedCompensationAggregateIntrinsicValueGranted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_81191b3d-5665-4ed3-9f8e-0c3879a12a5a" xlink:to="loc_htgc_ShareBasedCompensationAggregateIntrinsicValueGranted_4cfda828-1ac0-4026-99cf-a27d2a44aa47" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_4f81e67c-1b42-4796-bade-9ff23d7af3c2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_81191b3d-5665-4ed3-9f8e-0c3879a12a5a" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_4f81e67c-1b42-4796-bade-9ff23d7af3c2" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ShareBasedCompensationArrangementByShareBasedPaymentAwardDisposalPeriodAfterVesting_d0fc53a6-e0c8-4509-b0bf-2be620dd619e" xlink:href="htgc-20240630.xsd#htgc_ShareBasedCompensationArrangementByShareBasedPaymentAwardDisposalPeriodAfterVesting"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_81191b3d-5665-4ed3-9f8e-0c3879a12a5a" xlink:to="loc_htgc_ShareBasedCompensationArrangementByShareBasedPaymentAwardDisposalPeriodAfterVesting_d0fc53a6-e0c8-4509-b0bf-2be620dd619e" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_af965c90-0156-484b-97fe-7e3525c14b35" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_81191b3d-5665-4ed3-9f8e-0c3879a12a5a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_af965c90-0156-484b-97fe-7e3525c14b35" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ShareBasedCompensationArrangementByShareBasedPaymentAwardDistributionEquivalentUnitGrantDateFairValue_746bd875-25a6-4efa-8483-6c637a63e4c0" xlink:href="htgc-20240630.xsd#htgc_ShareBasedCompensationArrangementByShareBasedPaymentAwardDistributionEquivalentUnitGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_81191b3d-5665-4ed3-9f8e-0c3879a12a5a" xlink:to="loc_htgc_ShareBasedCompensationArrangementByShareBasedPaymentAwardDistributionEquivalentUnitGrantDateFairValue_746bd875-25a6-4efa-8483-6c637a63e4c0" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_401d7b64-68b8-4451-aad3-da862e8dc023" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_81191b3d-5665-4ed3-9f8e-0c3879a12a5a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_401d7b64-68b8-4451-aad3-da862e8dc023" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredCompensationSharebasedArrangementsLiabilityCurrentAndNoncurrent_f67e63d2-e762-468a-9bc4-224af3d05386" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredCompensationSharebasedArrangementsLiabilityCurrentAndNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_81191b3d-5665-4ed3-9f8e-0c3879a12a5a" xlink:to="loc_us-gaap_DeferredCompensationSharebasedArrangementsLiabilityCurrentAndNoncurrent_f67e63d2-e762-468a-9bc4-224af3d05386" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueVested_4baa00ba-3946-4df5-b191-faa3b7a20c7b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueVested"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_81191b3d-5665-4ed3-9f8e-0c3879a12a5a" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueVested_4baa00ba-3946-4df5-b191-faa3b7a20c7b" xlink:type="arc" order="13"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/EarningsPerShareScheduleofBasicandDilutedEarningsPerShareDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#EarningsPerShareScheduleofBasicandDilutedEarningsPerShareDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/EarningsPerShareScheduleofBasicandDilutedEarningsPerShareDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasicLineItems_a93e7a6d-a536-41a1-9639-ea60ca9d438d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EarningsPerShareBasicLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable_7ba49e73-28e7-4820-a385-41454607d8ac" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EarningsPerShareBasicLineItems_a93e7a6d-a536-41a1-9639-ea60ca9d438d" xlink:to="loc_us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable_7ba49e73-28e7-4820-a385-41454607d8ac" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_7a9dc9dd-a084-44af-90ad-92acdcff34a7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable_7ba49e73-28e7-4820-a385-41454607d8ac" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_7a9dc9dd-a084-44af-90ad-92acdcff34a7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_7a9dc9dd-a084-44af-90ad-92acdcff34a7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_7a9dc9dd-a084-44af-90ad-92acdcff34a7" xlink:to="loc_us-gaap_EquityComponentDomain_7a9dc9dd-a084-44af-90ad-92acdcff34a7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_e6e7a0d5-8bae-4358-9941-142d29ad7ed4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_7a9dc9dd-a084-44af-90ad-92acdcff34a7" xlink:to="loc_us-gaap_EquityComponentDomain_e6e7a0d5-8bae-4358-9941-142d29ad7ed4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_cf301d8c-0d7a-416c-94cf-8edb60bfb992" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_e6e7a0d5-8bae-4358-9941-142d29ad7ed4" xlink:to="loc_us-gaap_CommonStockMember_cf301d8c-0d7a-416c-94cf-8edb60bfb992" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_NumeratorForBasicAndDilutedChangeInNetAssetsPerCommonShareAbstract_edefa555-bc10-419d-b84c-d9595858aed5" xlink:href="htgc-20240630.xsd#htgc_NumeratorForBasicAndDilutedChangeInNetAssetsPerCommonShareAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicLineItems_a93e7a6d-a536-41a1-9639-ea60ca9d438d" xlink:to="loc_htgc_NumeratorForBasicAndDilutedChangeInNetAssetsPerCommonShareAbstract_edefa555-bc10-419d-b84c-d9595858aed5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_017e702d-fdb3-4cd0-a802-17f3b27bce4f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_NumeratorForBasicAndDilutedChangeInNetAssetsPerCommonShareAbstract_edefa555-bc10-419d-b84c-d9595858aed5" xlink:to="loc_us-gaap_NetIncomeLoss_017e702d-fdb3-4cd0-a802-17f3b27bce4f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyDividendDistribution_9b462ddb-1c81-4215-94ea-3c3ee7ec4b53" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentCompanyDividendDistribution"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_NumeratorForBasicAndDilutedChangeInNetAssetsPerCommonShareAbstract_edefa555-bc10-419d-b84c-d9595858aed5" xlink:to="loc_us-gaap_InvestmentCompanyDividendDistribution_9b462ddb-1c81-4215-94ea-3c3ee7ec4b53" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_bb1d4bfd-72ae-4782-80da-953b96313b57" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_NumeratorForBasicAndDilutedChangeInNetAssetsPerCommonShareAbstract_edefa555-bc10-419d-b84c-d9595858aed5" xlink:to="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_bb1d4bfd-72ae-4782-80da-953b96313b57" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_359834d6-60fe-41b2-b5ac-0dc8d2903fa2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_NumeratorForBasicAndDilutedChangeInNetAssetsPerCommonShareAbstract_edefa555-bc10-419d-b84c-d9595858aed5" xlink:to="loc_us-gaap_NetIncomeLossAvailableToCommonStockholdersDiluted_359834d6-60fe-41b2-b5ac-0dc8d2903fa2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UndistributedEarningsLossAvailableToCommonShareholdersBasic_f55d1819-d88d-4f3b-9892-292d2d68fada" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UndistributedEarningsLossAvailableToCommonShareholdersBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_NumeratorForBasicAndDilutedChangeInNetAssetsPerCommonShareAbstract_edefa555-bc10-419d-b84c-d9595858aed5" xlink:to="loc_us-gaap_UndistributedEarningsLossAvailableToCommonShareholdersBasic_f55d1819-d88d-4f3b-9892-292d2d68fada" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UndistributedEarnings_1157c0c0-f0ac-4a90-b927-def8c2f2c384" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UndistributedEarnings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_NumeratorForBasicAndDilutedChangeInNetAssetsPerCommonShareAbstract_edefa555-bc10-419d-b84c-d9595858aed5" xlink:to="loc_us-gaap_UndistributedEarnings_1157c0c0-f0ac-4a90-b927-def8c2f2c384" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract_f63f2b7c-8f6c-463b-b8d4-00f1aa847a21" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicLineItems_a93e7a6d-a536-41a1-9639-ea60ca9d438d" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract_f63f2b7c-8f6c-463b-b8d4-00f1aa847a21" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_112c0569-0230-4165-b77e-923c8cc2ec6d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract_f63f2b7c-8f6c-463b-b8d4-00f1aa847a21" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_112c0569-0230-4165-b77e-923c8cc2ec6d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_dbac07fd-a5e0-407a-b8b8-ea57f447bfc7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract_f63f2b7c-8f6c-463b-b8d4-00f1aa847a21" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_dbac07fd-a5e0-407a-b8b8-ea57f447bfc7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_56b5c1ee-c079-4232-9ee4-de87e7bc020e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract_f63f2b7c-8f6c-463b-b8d4-00f1aa847a21" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_56b5c1ee-c079-4232-9ee4-de87e7bc020e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ChangeInNetAssetsPerCommonShareAbstract_bcf2c2db-fdd3-4909-ac60-e8c89704b65f" xlink:href="htgc-20240630.xsd#htgc_ChangeInNetAssetsPerCommonShareAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingDilutedDisclosureItemsAbstract_f63f2b7c-8f6c-463b-b8d4-00f1aa847a21" xlink:to="loc_htgc_ChangeInNetAssetsPerCommonShareAbstract_bcf2c2db-fdd3-4909-ac60-e8c89704b65f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_906bfc18-ba5e-4a74-a45b-4a3afe0dc8d8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_ChangeInNetAssetsPerCommonShareAbstract_bcf2c2db-fdd3-4909-ac60-e8c89704b65f" xlink:to="loc_us-gaap_EarningsPerShareBasic_906bfc18-ba5e-4a74-a45b-4a3afe0dc8d8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_551f6416-575e-4a85-9ec9-4af924b84f87" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_ChangeInNetAssetsPerCommonShareAbstract_bcf2c2db-fdd3-4909-ac60-e8c89704b65f" xlink:to="loc_us-gaap_EarningsPerShareDiluted_551f6416-575e-4a85-9ec9-4af924b84f87" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/EarningsPerShareScheduleofNumberofAntidilutedSharesasCalculatedBasedonWeightedAverageClosingPriceofCommonStockDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#EarningsPerShareScheduleofNumberofAntidilutedSharesasCalculatedBasedonWeightedAverageClosingPriceofCommonStockDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/EarningsPerShareScheduleofNumberofAntidilutedSharesasCalculatedBasedonWeightedAverageClosingPriceofCommonStockDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_c877abbe-352e-4528-a0cd-10173fbc3e56" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_95d5fa6c-af7a-473c-81b0-76b4b98e0fde" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_c877abbe-352e-4528-a0cd-10173fbc3e56" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_95d5fa6c-af7a-473c-81b0-76b4b98e0fde" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_966362ca-8b11-48c9-b91e-a7f9411bea65" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_95d5fa6c-af7a-473c-81b0-76b4b98e0fde" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_966362ca-8b11-48c9-b91e-a7f9411bea65" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_966362ca-8b11-48c9-b91e-a7f9411bea65_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_966362ca-8b11-48c9-b91e-a7f9411bea65" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_966362ca-8b11-48c9-b91e-a7f9411bea65_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_d94d28c8-32ba-423b-8610-259283fbaf4b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_966362ca-8b11-48c9-b91e-a7f9411bea65" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_d94d28c8-32ba-423b-8610-259283fbaf4b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_44d821dc-6c29-4d9e-880c-664012f4f000" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_d94d28c8-32ba-423b-8610-259283fbaf4b" xlink:to="loc_us-gaap_EmployeeStockOptionMember_44d821dc-6c29-4d9e-880c-664012f4f000" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_7bebff0d-9608-481e-bea3-9eafc075ff8b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_d94d28c8-32ba-423b-8610-259283fbaf4b" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_7bebff0d-9608-481e-bea3-9eafc075ff8b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_UnvestedRestrictedStockAwardsMember_8718f850-4d1c-4398-b573-64037452fd04" xlink:href="htgc-20240630.xsd#htgc_UnvestedRestrictedStockAwardsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_d94d28c8-32ba-423b-8610-259283fbaf4b" xlink:to="loc_htgc_UnvestedRestrictedStockAwardsMember_8718f850-4d1c-4398-b573-64037452fd04" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_6ddb606c-f55b-4851-a512-2cc8c8c7f8a7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_c877abbe-352e-4528-a0cd-10173fbc3e56" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_6ddb606c-f55b-4851-a512-2cc8c8c7f8a7" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/FinancialHighlightsDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#FinancialHighlightsDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/FinancialHighlightsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyFinancialHighlightsLineItems_87c8401a-72c7-4ce8-8f93-4e753b833e3b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentCompanyFinancialHighlightsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyFinancialHighlightsTable_f4b99d88-8e1c-4010-9d41-b3cda023429e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentCompanyFinancialHighlightsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_InvestmentCompanyFinancialHighlightsLineItems_87c8401a-72c7-4ce8-8f93-4e753b833e3b" xlink:to="loc_us-gaap_InvestmentCompanyFinancialHighlightsTable_f4b99d88-8e1c-4010-9d41-b3cda023429e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_8bc8f389-0cc2-4c51-b88b-79014e7689f3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_InvestmentCompanyFinancialHighlightsTable_f4b99d88-8e1c-4010-9d41-b3cda023429e" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_8bc8f389-0cc2-4c51-b88b-79014e7689f3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_8bc8f389-0cc2-4c51-b88b-79014e7689f3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_8bc8f389-0cc2-4c51-b88b-79014e7689f3" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_8bc8f389-0cc2-4c51-b88b-79014e7689f3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_05e4612f-d929-4d29-a116-b14d562f256b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_8bc8f389-0cc2-4c51-b88b-79014e7689f3" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_05e4612f-d929-4d29-a116-b14d562f256b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_NetInvestmentIncomeMember_00860082-d58d-48cc-ad13-09170cfc426e" xlink:href="htgc-20240630.xsd#htgc_NetInvestmentIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_05e4612f-d929-4d29-a116-b14d562f256b" xlink:to="loc_htgc_NetInvestmentIncomeMember_00860082-d58d-48cc-ad13-09170cfc426e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_RealizedGainLossMember_65451b95-4828-4010-971a-011b8861f1d4" xlink:href="htgc-20240630.xsd#htgc_RealizedGainLossMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_05e4612f-d929-4d29-a116-b14d562f256b" xlink:to="loc_htgc_RealizedGainLossMember_65451b95-4828-4010-971a-011b8861f1d4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_UnrealizedGainLossMember_51de86fe-dc67-4a3f-b5ef-c82c9fff8b3c" xlink:href="htgc-20240630.xsd#htgc_UnrealizedGainLossMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_05e4612f-d929-4d29-a116-b14d562f256b" xlink:to="loc_htgc_UnrealizedGainLossMember_51de86fe-dc67-4a3f-b5ef-c82c9fff8b3c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyFinancialHighlightsRollForward_89af9a0b-5e2a-4cb6-af27-fc6132928966" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentCompanyFinancialHighlightsRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentCompanyFinancialHighlightsLineItems_87c8401a-72c7-4ce8-8f93-4e753b833e3b" xlink:to="loc_us-gaap_InvestmentCompanyFinancialHighlightsRollForward_89af9a0b-5e2a-4cb6-af27-fc6132928966" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyInvestmentIncomeLossFromOperationsPerShareAbstract_dacef116-89eb-4f34-93bc-31dfd35f69be" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentCompanyInvestmentIncomeLossFromOperationsPerShareAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentCompanyFinancialHighlightsRollForward_89af9a0b-5e2a-4cb6-af27-fc6132928966" xlink:to="loc_us-gaap_InvestmentCompanyInvestmentIncomeLossFromOperationsPerShareAbstract_dacef116-89eb-4f34-93bc-31dfd35f69be" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetAssetValuePerShare_dd5e968a-c147-45ac-bbac-4264b37fd68a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetAssetValuePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentCompanyInvestmentIncomeLossFromOperationsPerShareAbstract_dacef116-89eb-4f34-93bc-31dfd35f69be" xlink:to="loc_us-gaap_NetAssetValuePerShare_dd5e968a-c147-45ac-bbac-4264b37fd68a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyGainLossOnInvestmentPerShare_6d553a42-9904-483c-95f4-5ba3f8225c2d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentCompanyGainLossOnInvestmentPerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentCompanyInvestmentIncomeLossFromOperationsPerShareAbstract_dacef116-89eb-4f34-93bc-31dfd35f69be" xlink:to="loc_us-gaap_InvestmentCompanyGainLossOnInvestmentPerShare_6d553a42-9904-483c-95f4-5ba3f8225c2d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyInvestmentIncomeLossFromOperationsPerShare_aca53b1e-f6ce-4ad4-a5af-18add3af1507" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentCompanyInvestmentIncomeLossFromOperationsPerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentCompanyInvestmentIncomeLossFromOperationsPerShareAbstract_dacef116-89eb-4f34-93bc-31dfd35f69be" xlink:to="loc_us-gaap_InvestmentCompanyInvestmentIncomeLossFromOperationsPerShare_aca53b1e-f6ce-4ad4-a5af-18add3af1507" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_InvestmentCompanyCapitalShareTransactionIncreaseDecreasePerShare_b495394f-1968-41ea-89a2-9ef6f0889fe7" xlink:href="htgc-20240630.xsd#htgc_InvestmentCompanyCapitalShareTransactionIncreaseDecreasePerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentCompanyInvestmentIncomeLossFromOperationsPerShareAbstract_dacef116-89eb-4f34-93bc-31dfd35f69be" xlink:to="loc_htgc_InvestmentCompanyCapitalShareTransactionIncreaseDecreasePerShare_b495394f-1968-41ea-89a2-9ef6f0889fe7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_InvestmentCompanyDistributionToShareholdersPerShareExcludingCapitalShareTransactions_732bd2a1-4e94-49e2-923c-1eb2152b54d9" xlink:href="htgc-20240630.xsd#htgc_InvestmentCompanyDistributionToShareholdersPerShareExcludingCapitalShareTransactions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentCompanyInvestmentIncomeLossFromOperationsPerShareAbstract_dacef116-89eb-4f34-93bc-31dfd35f69be" xlink:to="loc_htgc_InvestmentCompanyDistributionToShareholdersPerShareExcludingCapitalShareTransactions_732bd2a1-4e94-49e2-923c-1eb2152b54d9" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_InvestmentCompanyStockBasedCompensationExpenseIncludedInInvestmentIncome_02c2baa7-899e-4bc2-8a1e-f542a2ae686c" xlink:href="htgc-20240630.xsd#htgc_InvestmentCompanyStockBasedCompensationExpenseIncludedInInvestmentIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentCompanyInvestmentIncomeLossFromOperationsPerShareAbstract_dacef116-89eb-4f34-93bc-31dfd35f69be" xlink:to="loc_htgc_InvestmentCompanyStockBasedCompensationExpenseIncludedInInvestmentIncome_02c2baa7-899e-4bc2-8a1e-f542a2ae686c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetAssetValuePerShare_46aaf102-88ef-4a06-8766-2a06756b5b4b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetAssetValuePerShare"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyFinancialRatiosAbstract_ace7c382-01c4-4fde-8cbb-49b683e5d702" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentCompanyFinancialRatiosAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentCompanyFinancialHighlightsRollForward_89af9a0b-5e2a-4cb6-af27-fc6132928966" xlink:to="loc_us-gaap_InvestmentCompanyFinancialRatiosAbstract_ace7c382-01c4-4fde-8cbb-49b683e5d702" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharePrice_9a3e67c6-ea18-4ec5-bba7-ad3e087029b6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentCompanyFinancialRatiosAbstract_ace7c382-01c4-4fde-8cbb-49b683e5d702" xlink:to="loc_us-gaap_SharePrice_9a3e67c6-ea18-4ec5-bba7-ad3e087029b6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyTotalReturn_aaf19a6d-f398-430b-a025-66de280d73e9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentCompanyTotalReturn"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentCompanyFinancialRatiosAbstract_ace7c382-01c4-4fde-8cbb-49b683e5d702" xlink:to="loc_us-gaap_InvestmentCompanyTotalReturn_aaf19a6d-f398-430b-a025-66de280d73e9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesOutstanding_5b83807b-9313-4468-b10d-f5371de8f6b7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentCompanyFinancialRatiosAbstract_ace7c382-01c4-4fde-8cbb-49b683e5d702" xlink:to="loc_us-gaap_SharesOutstanding_5b83807b-9313-4468-b10d-f5371de8f6b7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_09d317d7-ea74-4112-8d19-1d883e80cb31" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentCompanyFinancialRatiosAbstract_ace7c382-01c4-4fde-8cbb-49b683e5d702" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_09d317d7-ea74-4112-8d19-1d883e80cb31" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_89ceb250-4044-4f4b-b89b-dc48e47fa817" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentCompanyFinancialRatiosAbstract_ace7c382-01c4-4fde-8cbb-49b683e5d702" xlink:to="loc_us-gaap_StockholdersEquity_89ceb250-4044-4f4b-b89b-dc48e47fa817" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyExpenseRatioIncludingIncentiveFee_ab74f256-8c5c-4daf-b0c3-7e7fa19252da" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentCompanyExpenseRatioIncludingIncentiveFee"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentCompanyFinancialRatiosAbstract_ace7c382-01c4-4fde-8cbb-49b683e5d702" xlink:to="loc_us-gaap_InvestmentCompanyExpenseRatioIncludingIncentiveFee_ab74f256-8c5c-4daf-b0c3-7e7fa19252da" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyInvestmentIncomeLossRatio_572f2378-405a-42e9-a01e-6b1bf32f6291" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentCompanyInvestmentIncomeLossRatio"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentCompanyFinancialRatiosAbstract_ace7c382-01c4-4fde-8cbb-49b683e5d702" xlink:to="loc_us-gaap_InvestmentCompanyInvestmentIncomeLossRatio_572f2378-405a-42e9-a01e-6b1bf32f6291" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyPortfolioTurnover_d1ac2ded-0d41-436e-b863-d5c84960b2f5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentCompanyPortfolioTurnover"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentCompanyFinancialRatiosAbstract_ace7c382-01c4-4fde-8cbb-49b683e5d702" xlink:to="loc_us-gaap_InvestmentCompanyPortfolioTurnover_d1ac2ded-0d41-436e-b863-d5c84960b2f5" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtAverageAmountOutstanding_c7697eca-46e8-47e5-8ce4-474f669231ed" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebtAverageAmountOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentCompanyFinancialRatiosAbstract_ace7c382-01c4-4fde-8cbb-49b683e5d702" xlink:to="loc_us-gaap_LongTermDebtAverageAmountOutstanding_c7697eca-46e8-47e5-8ce4-474f669231ed" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_WeightedAverageDebtPerCommonShare_0eaa6a1f-e6cd-4ae8-869d-6ca4cace2253" xlink:href="htgc-20240630.xsd#htgc_WeightedAverageDebtPerCommonShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentCompanyFinancialRatiosAbstract_ace7c382-01c4-4fde-8cbb-49b683e5d702" xlink:to="loc_htgc_WeightedAverageDebtPerCommonShare_0eaa6a1f-e6cd-4ae8-869d-6ca4cace2253" xlink:type="arc" order="10"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/CommitmentsandContingenciesScheduleofUnfundedContractualCommitmentsDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#CommitmentsandContingenciesScheduleofUnfundedContractualCommitmentsDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/CommitmentsandContingenciesScheduleofUnfundedContractualCommitmentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesLineItems_37ec82e0-c59a-4eb0-a95c-8ab648a4e8d2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingenciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesTable_809734b8-7a98-409a-8f98-daf0fc27f46d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingenciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_37ec82e0-c59a-4eb0-a95c-8ab648a4e8d2" xlink:to="loc_us-gaap_LossContingenciesTable_809734b8-7a98-409a-8f98-daf0fc27f46d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_0251b279-d2b1-46ee-8f8f-fb7443da991e" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_809734b8-7a98-409a-8f98-daf0fc27f46d" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_0251b279-d2b1-46ee-8f8f-fb7443da991e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_0251b279-d2b1-46ee-8f8f-fb7443da991e_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_0251b279-d2b1-46ee-8f8f-fb7443da991e" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_0251b279-d2b1-46ee-8f8f-fb7443da991e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_0251b279-d2b1-46ee-8f8f-fb7443da991e" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ArmisInc.Member_06963a45-256b-49f7-96b4-e4487fdd4a20" xlink:href="htgc-20240630.xsd#htgc_ArmisInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_ArmisInc.Member_06963a45-256b-49f7-96b4-e4487fdd4a20" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_EarnixLtdMember_396164c9-f583-4458-a2c5-b1a95dc02673" xlink:href="htgc-20240630.xsd#htgc_EarnixLtdMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_EarnixLtdMember_396164c9-f583-4458-a2c5-b1a95dc02673" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ThumbtackInc.Member_24a6bba3-f43a-4fa8-a8af-4392c04a5088" xlink:href="htgc-20240630.xsd#htgc_ThumbtackInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_ThumbtackInc.Member_24a6bba3-f43a-4fa8-a8af-4392c04a5088" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_AutomationAnywhereInc.Member_7763d292-c713-4ea2-93b0-d8bf6c4e763f" xlink:href="htgc-20240630.xsd#htgc_AutomationAnywhereInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_AutomationAnywhereInc.Member_7763d292-c713-4ea2-93b0-d8bf6c4e763f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CheckrGroupInc.Member_a2f7094c-d1d9-4678-8c90-018eb4b6d382" xlink:href="htgc-20240630.xsd#htgc_CheckrGroupInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_CheckrGroupInc.Member_a2f7094c-d1d9-4678-8c90-018eb4b6d382" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SkydioInc.Member_17d19c30-d486-48c0-8d62-13f406067043" xlink:href="htgc-20240630.xsd#htgc_SkydioInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_SkydioInc.Member_17d19c30-d486-48c0-8d62-13f406067043" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_HilleVaxInc.Member_35c32724-b774-450e-88e2-fd387ac8b050" xlink:href="htgc-20240630.xsd#htgc_HilleVaxInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_HilleVaxInc.Member_35c32724-b774-450e-88e2-fd387ac8b050" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_PindropSecurityInc.Member_c0ddd6d9-b198-4fe7-baa3-41abba699fe5" xlink:href="htgc-20240630.xsd#htgc_PindropSecurityInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_PindropSecurityInc.Member_c0ddd6d9-b198-4fe7-baa3-41abba699fe5" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ShieldAIInc.Member_28e893ec-aaa5-46a6-9828-ed9c5fc7aa5a" xlink:href="htgc-20240630.xsd#htgc_ShieldAIInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_ShieldAIInc.Member_28e893ec-aaa5-46a6-9828-ed9c5fc7aa5a" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_PhathomPharmaceuticalsInc.Member_582f23b8-7c76-4389-980f-1d0fb7ebf13d" xlink:href="htgc-20240630.xsd#htgc_PhathomPharmaceuticalsInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_PhathomPharmaceuticalsInc.Member_582f23b8-7c76-4389-980f-1d0fb7ebf13d" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_AkeroTherapeuticsInc.Member_03fa0dd8-d207-4984-8181-557c0974aff2" xlink:href="htgc-20240630.xsd#htgc_AkeroTherapeuticsInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_AkeroTherapeuticsInc.Member_03fa0dd8-d207-4984-8181-557c0974aff2" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SemperisTechnologiesInc.Member_ad04cd19-a9d6-4d2e-be6f-e35e1f604d8c" xlink:href="htgc-20240630.xsd#htgc_SemperisTechnologiesInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_SemperisTechnologiesInc.Member_ad04cd19-a9d6-4d2e-be6f-e35e1f604d8c" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MainStreetRuralInc.Member_b1fa4943-1c00-4082-97b4-10fe052866d0" xlink:href="htgc-20240630.xsd#htgc_MainStreetRuralInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_MainStreetRuralInc.Member_b1fa4943-1c00-4082-97b4-10fe052866d0" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DragosMember_a3ff4247-8085-47dc-9224-f1197f1373da" xlink:href="htgc-20240630.xsd#htgc_DragosMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_DragosMember_a3ff4247-8085-47dc-9224-f1197f1373da" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_HarnessInc.Member_a0f7ff18-1074-4153-99f6-8ca6546fd219" xlink:href="htgc-20240630.xsd#htgc_HarnessInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_HarnessInc.Member_a0f7ff18-1074-4153-99f6-8ca6546fd219" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MarathonHealthLLCMember_51de708f-a55d-42cf-b2e2-9371a9d421ba" xlink:href="htgc-20240630.xsd#htgc_MarathonHealthLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_MarathonHealthLLCMember_51de708f-a55d-42cf-b2e2-9371a9d421ba" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SuzyInc.Member_32a87de1-e4b0-4359-8647-19259677a439" xlink:href="htgc-20240630.xsd#htgc_SuzyInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_SuzyInc.Member_32a87de1-e4b0-4359-8647-19259677a439" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ReveleerMember_d5fe7b79-de42-465b-ab56-78a219568fec" xlink:href="htgc-20240630.xsd#htgc_ReveleerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_ReveleerMember_d5fe7b79-de42-465b-ab56-78a219568fec" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_WellBeSeniorMedicalLLCMember_7f072468-7004-4681-ace7-d492ac246b8f" xlink:href="htgc-20240630.xsd#htgc_WellBeSeniorMedicalLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_WellBeSeniorMedicalLLCMember_7f072468-7004-4681-ace7-d492ac246b8f" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_GeronCorporationMember_3625fe6d-d1f6-4316-8068-279a8b9aacaa" xlink:href="htgc-20240630.xsd#htgc_GeronCorporationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_GeronCorporationMember_3625fe6d-d1f6-4316-8068-279a8b9aacaa" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SaamaTechnologiesLLCMember_d775451e-cf07-4cf5-a78f-ca4c0a925ad1" xlink:href="htgc-20240630.xsd#htgc_SaamaTechnologiesLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_SaamaTechnologiesLLCMember_d775451e-cf07-4cf5-a78f-ca4c0a925ad1" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ElationHealthInc.Member_13c7fe9d-c96d-40de-9494-00ea39beef1d" xlink:href="htgc-20240630.xsd#htgc_ElationHealthInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_ElationHealthInc.Member_13c7fe9d-c96d-40de-9494-00ea39beef1d" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CuranaHealthHoldingsLLCMember_1aff5355-d7c8-4999-84c0-fdd168f76cc8" xlink:href="htgc-20240630.xsd#htgc_CuranaHealthHoldingsLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_CuranaHealthHoldingsLLCMember_1aff5355-d7c8-4999-84c0-fdd168f76cc8" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ATAILifeSciencesN.V.Member_f5d96578-c538-44fd-964d-6146a93f3a67" xlink:href="htgc-20240630.xsd#htgc_ATAILifeSciencesN.V.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_ATAILifeSciencesN.V.Member_f5d96578-c538-44fd-964d-6146a93f3a67" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_LeapworkApSMember_b81e80ae-3475-4001-b24f-281c0c28a605" xlink:href="htgc-20240630.xsd#htgc_LeapworkApSMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_LeapworkApSMember_b81e80ae-3475-4001-b24f-281c0c28a605" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_BraeburnPharmaceuticalsMember_d9785cff-c551-4249-a644-bab06a281fd4" xlink:href="htgc-20240630.xsd#htgc_BraeburnPharmaceuticalsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_BraeburnPharmaceuticalsMember_d9785cff-c551-4249-a644-bab06a281fd4" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_BabelStreetMember_be591b32-f2ad-4db5-8185-4733daf190d6" xlink:href="htgc-20240630.xsd#htgc_BabelStreetMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_BabelStreetMember_be591b32-f2ad-4db5-8185-4733daf190d6" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_HeronTherapeuticsInc.Member_1ed30979-0077-4fef-8fd4-5bc37166f895" xlink:href="htgc-20240630.xsd#htgc_HeronTherapeuticsInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_HeronTherapeuticsInc.Member_1ed30979-0077-4fef-8fd4-5bc37166f895" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_AlphaSenseInc.Member_a81aa06c-e941-439a-8905-20d99fa70a9c" xlink:href="htgc-20240630.xsd#htgc_AlphaSenseInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_AlphaSenseInc.Member_a81aa06c-e941-439a-8905-20d99fa70a9c" xlink:type="arc" order="28"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_AllvueSystemsLLCMember_8d91dc21-d8b2-44a8-be32-1b30c30d5c45" xlink:href="htgc-20240630.xsd#htgc_AllvueSystemsLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_AllvueSystemsLLCMember_8d91dc21-d8b2-44a8-be32-1b30c30d5c45" xlink:type="arc" order="29"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SightSciencesInc.Member_2770d981-706c-4140-8bcb-46fa3215057c" xlink:href="htgc-20240630.xsd#htgc_SightSciencesInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_SightSciencesInc.Member_2770d981-706c-4140-8bcb-46fa3215057c" xlink:type="arc" order="30"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DronedeployInc.Member_4b5dc8ba-7b1c-4951-b0b0-b712057b96fa" xlink:href="htgc-20240630.xsd#htgc_DronedeployInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_DronedeployInc.Member_4b5dc8ba-7b1c-4951-b0b0-b712057b96fa" xlink:type="arc" order="31"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_RivieraPartnersLLCMember_3f3a210f-8a12-45d6-b065-54c63a2c022d" xlink:href="htgc-20240630.xsd#htgc_RivieraPartnersLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_RivieraPartnersLLCMember_3f3a210f-8a12-45d6-b065-54c63a2c022d" xlink:type="arc" order="32"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_LoftwareInc.Member_5ebad582-d1b3-4850-8968-0e40f9af409b" xlink:href="htgc-20240630.xsd#htgc_LoftwareInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_LoftwareInc.Member_5ebad582-d1b3-4850-8968-0e40f9af409b" xlink:type="arc" order="33"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ZappiInc.Member_cf35becd-de1b-4a8a-91da-f7bc28b08a6d" xlink:href="htgc-20240630.xsd#htgc_ZappiInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_ZappiInc.Member_cf35becd-de1b-4a8a-91da-f7bc28b08a6d" xlink:type="arc" order="34"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_AltumintInc.Member_003160da-bbfe-4c30-a5f3-b77b14f3ca4b" xlink:href="htgc-20240630.xsd#htgc_AltumintInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_AltumintInc.Member_003160da-bbfe-4c30-a5f3-b77b14f3ca4b" xlink:type="arc" order="35"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_StreamlineHealthcareSolutionsMember_ca7f2e56-af1e-4b9f-951a-5bbf5871648a" xlink:href="htgc-20240630.xsd#htgc_StreamlineHealthcareSolutionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_StreamlineHealthcareSolutionsMember_ca7f2e56-af1e-4b9f-951a-5bbf5871648a" xlink:type="arc" order="36"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_NewRelicInc.Member_6690b570-0264-48f3-9ae9-bf3d9a507323" xlink:href="htgc-20240630.xsd#htgc_NewRelicInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_NewRelicInc.Member_6690b570-0264-48f3-9ae9-bf3d9a507323" xlink:type="arc" order="37"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SumoLogicInc.Member_bdec1917-3cb7-49b5-9092-cd87025e361a" xlink:href="htgc-20240630.xsd#htgc_SumoLogicInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_SumoLogicInc.Member_bdec1917-3cb7-49b5-9092-cd87025e361a" xlink:type="arc" order="38"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SandataTechnologiesLLCMember_6ec166bf-b58a-4207-b744-959d59d8f5d3" xlink:href="htgc-20240630.xsd#htgc_SandataTechnologiesLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_SandataTechnologiesLLCMember_6ec166bf-b58a-4207-b744-959d59d8f5d3" xlink:type="arc" order="39"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CerosInc.Member_dd497875-90f1-4442-9ec4-a61f4c542142" xlink:href="htgc-20240630.xsd#htgc_CerosInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_CerosInc.Member_dd497875-90f1-4442-9ec4-a61f4c542142" xlink:type="arc" order="40"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ThreatConnectInc.Member_408f31aa-56b8-4423-ae32-bdddc113e333" xlink:href="htgc-20240630.xsd#htgc_ThreatConnectInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_ThreatConnectInc.Member_408f31aa-56b8-4423-ae32-bdddc113e333" xlink:type="arc" order="41"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_LogicSourceMember_fa8ed9bc-0030-46c7-8b25-6e96c70c46c2" xlink:href="htgc-20240630.xsd#htgc_LogicSourceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_LogicSourceMember_fa8ed9bc-0030-46c7-8b25-6e96c70c46c2" xlink:type="arc" order="42"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ZimperiumInc.Member_0e718179-a96f-49e2-b64c-cc68cd26dda3" xlink:href="htgc-20240630.xsd#htgc_ZimperiumInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_ZimperiumInc.Member_0e718179-a96f-49e2-b64c-cc68cd26dda3" xlink:type="arc" order="43"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_IkonScienceLimitedMember_18fd7172-683a-4c14-9f58-ef1b2c946f5a" xlink:href="htgc-20240630.xsd#htgc_IkonScienceLimitedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_IkonScienceLimitedMember_18fd7172-683a-4c14-9f58-ef1b2c946f5a" xlink:type="arc" order="44"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_LinenMasterLLCMember_3f89e188-058c-4200-80cb-af56e252c7c2" xlink:href="htgc-20240630.xsd#htgc_LinenMasterLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_LinenMasterLLCMember_3f89e188-058c-4200-80cb-af56e252c7c2" xlink:type="arc" order="45"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_FortifiedHealthSecurityMember_98a8d620-53e2-4ead-8ae0-53d78a60c690" xlink:href="htgc-20240630.xsd#htgc_FortifiedHealthSecurityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_FortifiedHealthSecurityMember_98a8d620-53e2-4ead-8ae0-53d78a60c690" xlink:type="arc" order="46"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DispatchTechnologiesInc.Member_c0fd6a1f-59ba-45f9-a855-a5a8bc565b8d" xlink:href="htgc-20240630.xsd#htgc_DispatchTechnologiesInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_DispatchTechnologiesInc.Member_c0fd6a1f-59ba-45f9-a855-a5a8bc565b8d" xlink:type="arc" order="47"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_OmedaHoldingsLLCMember_c5284cb3-5a95-42ed-901e-ba05771a9389" xlink:href="htgc-20240630.xsd#htgc_OmedaHoldingsLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_OmedaHoldingsLLCMember_c5284cb3-5a95-42ed-901e-ba05771a9389" xlink:type="arc" order="48"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_FlightScheduleProLLCMember_f4f863af-0f08-43fb-9621-b94655f56554" xlink:href="htgc-20240630.xsd#htgc_FlightScheduleProLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_FlightScheduleProLLCMember_f4f863af-0f08-43fb-9621-b94655f56554" xlink:type="arc" order="49"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_Constructor.ioCorporationMember_d2a47be8-f408-4db0-878b-1e4a7ff5381d" xlink:href="htgc-20240630.xsd#htgc_Constructor.ioCorporationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_Constructor.ioCorporationMember_d2a47be8-f408-4db0-878b-1e4a7ff5381d" xlink:type="arc" order="50"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ShadowDragonLLCMember_d8735fb3-bd00-41c6-b387-e8b556fa5c45" xlink:href="htgc-20240630.xsd#htgc_ShadowDragonLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_ShadowDragonLLCMember_d8735fb3-bd00-41c6-b387-e8b556fa5c45" xlink:type="arc" order="51"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CybermaxxIntermediateHoldingsInc.Member_3a8bd354-3ec6-4b1c-9b01-c2d09ebf2c45" xlink:href="htgc-20240630.xsd#htgc_CybermaxxIntermediateHoldingsInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_CybermaxxIntermediateHoldingsInc.Member_3a8bd354-3ec6-4b1c-9b01-c2d09ebf2c45" xlink:type="arc" order="52"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_NorthSeaTherapeuticsB.VMember_623d27d0-2fa9-41a1-bbc8-3f6fb52348ee" xlink:href="htgc-20240630.xsd#htgc_NorthSeaTherapeuticsB.VMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_NorthSeaTherapeuticsB.VMember_623d27d0-2fa9-41a1-bbc8-3f6fb52348ee" xlink:type="arc" order="53"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_A3GTMSLLCMember_01e54672-2f90-4b4b-8b73-ee3cdfd37b0c" xlink:href="htgc-20240630.xsd#htgc_A3GTMSLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_A3GTMSLLCMember_01e54672-2f90-4b4b-8b73-ee3cdfd37b0c" xlink:type="arc" order="54"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CytracomHoldingsLLCMember_2805df0f-909e-471f-bec1-dfe12ca8b808" xlink:href="htgc-20240630.xsd#htgc_CytracomHoldingsLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_CytracomHoldingsLLCMember_2805df0f-909e-471f-bec1-dfe12ca8b808" xlink:type="arc" order="55"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TarsusPharmaceuticalsInc.Member_efc83e89-a572-48fe-b8fb-e9f1c7bb58c0" xlink:href="htgc-20240630.xsd#htgc_TarsusPharmaceuticalsInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_TarsusPharmaceuticalsInc.Member_efc83e89-a572-48fe-b8fb-e9f1c7bb58c0" xlink:type="arc" order="56"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_KuraOncologyInc.Member_2b5c0469-8370-4460-ac74-d3f38a68e5c4" xlink:href="htgc-20240630.xsd#htgc_KuraOncologyInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_KuraOncologyInc.Member_2b5c0469-8370-4460-ac74-d3f38a68e5c4" xlink:type="arc" order="57"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TipaltiSolutionsLtd.Member_f4bf999b-be98-4ab8-8371-e5b870fa5c30" xlink:href="htgc-20240630.xsd#htgc_TipaltiSolutionsLtd.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_TipaltiSolutionsLtd.Member_f4bf999b-be98-4ab8-8371-e5b870fa5c30" xlink:type="arc" order="58"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_NextInsuranceInc.Member_13c76897-6f74-4eec-bb6c-331408d29144" xlink:href="htgc-20240630.xsd#htgc_NextInsuranceInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_NextInsuranceInc.Member_13c76897-6f74-4eec-bb6c-331408d29144" xlink:type="arc" order="59"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SenseonicsHoldingsInc.Member_275d33f8-a973-4c52-b644-439d4ab46b59" xlink:href="htgc-20240630.xsd#htgc_SenseonicsHoldingsInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_SenseonicsHoldingsInc.Member_275d33f8-a973-4c52-b644-439d4ab46b59" xlink:type="arc" order="60"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ModernLifeInc.Member_3ec4c0f2-a3fe-405c-8fa4-d2e640c0cff6" xlink:href="htgc-20240630.xsd#htgc_ModernLifeInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_ModernLifeInc.Member_3ec4c0f2-a3fe-405c-8fa4-d2e640c0cff6" xlink:type="arc" order="61"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_BrainCorporationMember_ca0ff8b5-08d1-45ae-9dca-eb784ef2f315" xlink:href="htgc-20240630.xsd#htgc_BrainCorporationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_BrainCorporationMember_ca0ff8b5-08d1-45ae-9dca-eb784ef2f315" xlink:type="arc" order="62"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CutoverInc.Member_62a88367-d225-42b0-b872-94a8a95b00f8" xlink:href="htgc-20240630.xsd#htgc_CutoverInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_CutoverInc.Member_62a88367-d225-42b0-b872-94a8a95b00f8" xlink:type="arc" order="63"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_PlentificLtdMember_b60fe493-8f55-4e10-b80c-4215cdd60561" xlink:href="htgc-20240630.xsd#htgc_PlentificLtdMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_PlentificLtdMember_b60fe493-8f55-4e10-b80c-4215cdd60561" xlink:type="arc" order="64"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_YipitLLCMember_cfc87355-80b2-44f4-818b-65303062e1f4" xlink:href="htgc-20240630.xsd#htgc_YipitLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_YipitLLCMember_cfc87355-80b2-44f4-818b-65303062e1f4" xlink:type="arc" order="65"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DashlaneInc.Member_948cd713-5d55-4082-ad11-e6d934bd6291" xlink:href="htgc-20240630.xsd#htgc_DashlaneInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_DashlaneInc.Member_948cd713-5d55-4082-ad11-e6d934bd6291" xlink:type="arc" order="66"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_AnnexCloudMember_234b8e93-7263-44e8-bf97-11199242a61d" xlink:href="htgc-20240630.xsd#htgc_AnnexCloudMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_AnnexCloudMember_234b8e93-7263-44e8-bf97-11199242a61d" xlink:type="arc" order="67"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_AgilenceInc.Member_2546a16f-9c92-48fe-b36c-f9111cf494b3" xlink:href="htgc-20240630.xsd#htgc_AgilenceInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_AgilenceInc.Member_2546a16f-9c92-48fe-b36c-f9111cf494b3" xlink:type="arc" order="68"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_EnmarkSystemsInc.Member_cda7c5a2-91db-4fb0-883b-4c79409c484e" xlink:href="htgc-20240630.xsd#htgc_EnmarkSystemsInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_EnmarkSystemsInc.Member_cda7c5a2-91db-4fb0-883b-4c79409c484e" xlink:type="arc" order="69"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_AlchemerLLCMember_e9dc758f-0ede-462b-8258-ef03a9bba6aa" xlink:href="htgc-20240630.xsd#htgc_AlchemerLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_AlchemerLLCMember_e9dc758f-0ede-462b-8258-ef03a9bba6aa" xlink:type="arc" order="70"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ForbionGrowthOpportunitiesFundICVMember_e275efa5-35c5-4ab2-aea6-394642a9f7f4" xlink:href="htgc-20240630.xsd#htgc_ForbionGrowthOpportunitiesFundICVMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_ForbionGrowthOpportunitiesFundICVMember_e275efa5-35c5-4ab2-aea6-394642a9f7f4" xlink:type="arc" order="71"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ForbionGrowthOpportunitiesFundIICVMember_1627590e-44d2-4bcc-842f-4da2350e5215" xlink:href="htgc-20240630.xsd#htgc_ForbionGrowthOpportunitiesFundIICVMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_db321642-2886-4c86-80e9-4fa30da84f90" xlink:to="loc_htgc_ForbionGrowthOpportunitiesFundIICVMember_1627590e-44d2-4bcc-842f-4da2350e5215" xlink:type="arc" order="72"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityAxis_3df16434-f385-4605-ad56-166c1e7b5f2a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialSupportToNonconsolidatedLegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_809734b8-7a98-409a-8f98-daf0fc27f46d" xlink:to="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityAxis_3df16434-f385-4605-ad56-166c1e7b5f2a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityDomain_3df16434-f385-4605-ad56-166c1e7b5f2a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialSupportToNonconsolidatedLegalEntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityAxis_3df16434-f385-4605-ad56-166c1e7b5f2a" xlink:to="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityDomain_3df16434-f385-4605-ad56-166c1e7b5f2a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityDomain_0d275277-976e-4df4-a6b4-93cd0748576a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialSupportToNonconsolidatedLegalEntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityAxis_3df16434-f385-4605-ad56-166c1e7b5f2a" xlink:to="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityDomain_0d275277-976e-4df4-a6b4-93cd0748576a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DebtInvestmentsMember_166fc765-2115-4ba6-ba7b-cf01a7dbe8c2" xlink:href="htgc-20240630.xsd#htgc_DebtInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityDomain_0d275277-976e-4df4-a6b4-93cd0748576a" xlink:to="loc_htgc_DebtInvestmentsMember_166fc765-2115-4ba6-ba7b-cf01a7dbe8c2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_InvestmentFundsAndVehiclesMember_cbf8a61b-b621-42c7-a856-90cfe5470870" xlink:href="htgc-20240630.xsd#htgc_InvestmentFundsAndVehiclesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityDomain_0d275277-976e-4df4-a6b4-93cd0748576a" xlink:to="loc_htgc_InvestmentFundsAndVehiclesMember_cbf8a61b-b621-42c7-a856-90cfe5470870" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_AdviserFundsMember_81ae8e99-a75d-452c-aecc-a0747d06aa29" xlink:href="htgc-20240630.xsd#htgc_AdviserFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityDomain_0d275277-976e-4df4-a6b4-93cd0748576a" xlink:to="loc_htgc_AdviserFundsMember_81ae8e99-a75d-452c-aecc-a0747d06aa29" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyFinancialCommitmentToInvesteeFutureAmount_6b5ca873-b91f-4324-853c-148013c1331a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentCompanyFinancialCommitmentToInvesteeFutureAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_37ec82e0-c59a-4eb0-a95c-8ab648a4e8d2" xlink:to="loc_us-gaap_InvestmentCompanyFinancialCommitmentToInvesteeFutureAmount_6b5ca873-b91f-4324-853c-148013c1331a" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/CommitmentsandContingenciesScheduleofUnencumberedUnfundedCommitmentsDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#CommitmentsandContingenciesScheduleofUnencumberedUnfundedCommitmentsDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/CommitmentsandContingenciesScheduleofUnencumberedUnfundedCommitmentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CommitmentsAndContingenciesLineItems_6c084900-4587-40de-8a51-4db33c2aa22b" xlink:href="htgc-20240630.xsd#htgc_CommitmentsAndContingenciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CommitmentsAndContingenciesTable_4419c20d-d756-4bee-a7fe-2858c79174e5" xlink:href="htgc-20240630.xsd#htgc_CommitmentsAndContingenciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_htgc_CommitmentsAndContingenciesLineItems_6c084900-4587-40de-8a51-4db33c2aa22b" xlink:to="loc_htgc_CommitmentsAndContingenciesTable_4419c20d-d756-4bee-a7fe-2858c79174e5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityAxis_b98f2661-ffc6-4a78-9678-95380d9fef73" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialSupportToNonconsolidatedLegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_htgc_CommitmentsAndContingenciesTable_4419c20d-d756-4bee-a7fe-2858c79174e5" xlink:to="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityAxis_b98f2661-ffc6-4a78-9678-95380d9fef73" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityDomain_b98f2661-ffc6-4a78-9678-95380d9fef73_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialSupportToNonconsolidatedLegalEntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityAxis_b98f2661-ffc6-4a78-9678-95380d9fef73" xlink:to="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityDomain_b98f2661-ffc6-4a78-9678-95380d9fef73_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityDomain_66a20114-6c5e-4eec-8dc3-75ba0dc5bd45" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialSupportToNonconsolidatedLegalEntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityAxis_b98f2661-ffc6-4a78-9678-95380d9fef73" xlink:to="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityDomain_66a20114-6c5e-4eec-8dc3-75ba0dc5bd45" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DebtInvestmentsMember_ebb3d70d-311c-4516-aa25-f687edb8c82d" xlink:href="htgc-20240630.xsd#htgc_DebtInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityDomain_66a20114-6c5e-4eec-8dc3-75ba0dc5bd45" xlink:to="loc_htgc_DebtInvestmentsMember_ebb3d70d-311c-4516-aa25-f687edb8c82d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_InvestmentFundsAndVehiclesMember_133f82ce-e1d1-4cd2-8683-2905724e3ec3" xlink:href="htgc-20240630.xsd#htgc_InvestmentFundsAndVehiclesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityDomain_66a20114-6c5e-4eec-8dc3-75ba0dc5bd45" xlink:to="loc_htgc_InvestmentFundsAndVehiclesMember_133f82ce-e1d1-4cd2-8683-2905724e3ec3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_UnfundedCommitmentsDueInRemainderOfFiscalYear_2cc85c02-84b9-4ec0-b015-7ec8fdd799e0" xlink:href="htgc-20240630.xsd#htgc_UnfundedCommitmentsDueInRemainderOfFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_CommitmentsAndContingenciesLineItems_6c084900-4587-40de-8a51-4db33c2aa22b" xlink:to="loc_htgc_UnfundedCommitmentsDueInRemainderOfFiscalYear_2cc85c02-84b9-4ec0-b015-7ec8fdd799e0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_UnfundedCommitmentsDueInSecondYear_9de2d6dd-49bf-4369-baf9-b6d8654f5c33" xlink:href="htgc-20240630.xsd#htgc_UnfundedCommitmentsDueInSecondYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_CommitmentsAndContingenciesLineItems_6c084900-4587-40de-8a51-4db33c2aa22b" xlink:to="loc_htgc_UnfundedCommitmentsDueInSecondYear_9de2d6dd-49bf-4369-baf9-b6d8654f5c33" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_UnfundedCommitmentsDueInThirdYear_d96bd098-1010-4114-8ac7-e17b2ff380ff" xlink:href="htgc-20240630.xsd#htgc_UnfundedCommitmentsDueInThirdYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_CommitmentsAndContingenciesLineItems_6c084900-4587-40de-8a51-4db33c2aa22b" xlink:to="loc_htgc_UnfundedCommitmentsDueInThirdYear_d96bd098-1010-4114-8ac7-e17b2ff380ff" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_UnfundedCommitmentsDueInFourthYear_356987f9-ed7e-4509-a759-cd82716a794f" xlink:href="htgc-20240630.xsd#htgc_UnfundedCommitmentsDueInFourthYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_CommitmentsAndContingenciesLineItems_6c084900-4587-40de-8a51-4db33c2aa22b" xlink:to="loc_htgc_UnfundedCommitmentsDueInFourthYear_356987f9-ed7e-4509-a759-cd82716a794f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_UnfundedCommitmentsDueInFifthYear_71596d0e-81a1-47fe-8cdd-f153d22fb54b" xlink:href="htgc-20240630.xsd#htgc_UnfundedCommitmentsDueInFifthYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_CommitmentsAndContingenciesLineItems_6c084900-4587-40de-8a51-4db33c2aa22b" xlink:to="loc_htgc_UnfundedCommitmentsDueInFifthYear_71596d0e-81a1-47fe-8cdd-f153d22fb54b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_UnfundedCommitmentsDueInSixthYear_4a6e9188-b251-414b-a388-073c24a781e7" xlink:href="htgc-20240630.xsd#htgc_UnfundedCommitmentsDueInSixthYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_CommitmentsAndContingenciesLineItems_6c084900-4587-40de-8a51-4db33c2aa22b" xlink:to="loc_htgc_UnfundedCommitmentsDueInSixthYear_4a6e9188-b251-414b-a388-073c24a781e7" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_UnfundedCommitmentsDueInSeventhYear_9e3965ac-91a4-4c3e-a92b-10a9777b6198" xlink:href="htgc-20240630.xsd#htgc_UnfundedCommitmentsDueInSeventhYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_CommitmentsAndContingenciesLineItems_6c084900-4587-40de-8a51-4db33c2aa22b" xlink:to="loc_htgc_UnfundedCommitmentsDueInSeventhYear_9e3965ac-91a4-4c3e-a92b-10a9777b6198" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_UnfundedCommitmentsDueInNinthYear_e734bb23-3df5-4c4a-900f-fca235f64964" xlink:href="htgc-20240630.xsd#htgc_UnfundedCommitmentsDueInNinthYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_CommitmentsAndContingenciesLineItems_6c084900-4587-40de-8a51-4db33c2aa22b" xlink:to="loc_htgc_UnfundedCommitmentsDueInNinthYear_e734bb23-3df5-4c4a-900f-fca235f64964" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentCompanyFinancialCommitmentToInvesteeFutureAmount_ac8a2b5a-22aa-4fd4-8387-0726e4530170" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentCompanyFinancialCommitmentToInvesteeFutureAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_CommitmentsAndContingenciesLineItems_6c084900-4587-40de-8a51-4db33c2aa22b" xlink:to="loc_us-gaap_InvestmentCompanyFinancialCommitmentToInvesteeFutureAmount_ac8a2b5a-22aa-4fd4-8387-0726e4530170" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/CommitmentsandContingenciesScheduleofContractualObligationsDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#CommitmentsandContingenciesScheduleofContractualObligationsDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/CommitmentsandContingenciesScheduleofContractualObligationsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CommitmentsAndContingenciesLineItems_cb30ec9f-7b2b-464e-94df-46dfac8f4a8e" xlink:href="htgc-20240630.xsd#htgc_CommitmentsAndContingenciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CommitmentsAndContingenciesTable_4ea185c8-e080-4479-9fa6-85576350f4fb" xlink:href="htgc-20240630.xsd#htgc_CommitmentsAndContingenciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_htgc_CommitmentsAndContingenciesLineItems_cb30ec9f-7b2b-464e-94df-46dfac8f4a8e" xlink:to="loc_htgc_CommitmentsAndContingenciesTable_4ea185c8-e080-4479-9fa6-85576350f4fb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityAxis_e3a2fc4c-0b98-4764-944c-258657747dfd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialSupportToNonconsolidatedLegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_htgc_CommitmentsAndContingenciesTable_4ea185c8-e080-4479-9fa6-85576350f4fb" xlink:to="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityAxis_e3a2fc4c-0b98-4764-944c-258657747dfd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityDomain_e3a2fc4c-0b98-4764-944c-258657747dfd_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialSupportToNonconsolidatedLegalEntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityAxis_e3a2fc4c-0b98-4764-944c-258657747dfd" xlink:to="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityDomain_e3a2fc4c-0b98-4764-944c-258657747dfd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityDomain_b9bc4318-4c57-4619-935d-ea11ac0a2433" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialSupportToNonconsolidatedLegalEntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityAxis_e3a2fc4c-0b98-4764-944c-258657747dfd" xlink:to="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityDomain_b9bc4318-4c57-4619-935d-ea11ac0a2433" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DebtInvestmentsMember_e802e009-d946-4795-9330-a084ed094c84" xlink:href="htgc-20240630.xsd#htgc_DebtInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityDomain_b9bc4318-4c57-4619-935d-ea11ac0a2433" xlink:to="loc_htgc_DebtInvestmentsMember_e802e009-d946-4795-9330-a084ed094c84" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_LeaseAndLicenseObligationsMember_03d1f0f9-a00b-4ea3-86c3-8414dbbe895f" xlink:href="htgc-20240630.xsd#htgc_LeaseAndLicenseObligationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialSupportToNonconsolidatedLegalEntityDomain_b9bc4318-4c57-4619-935d-ea11ac0a2433" xlink:to="loc_htgc_LeaseAndLicenseObligationsMember_03d1f0f9-a00b-4ea3-86c3-8414dbbe895f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_f5eff12e-32ab-487c-88d8-4e9a68481720" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_htgc_CommitmentsAndContingenciesTable_4ea185c8-e080-4479-9fa6-85576350f4fb" xlink:to="loc_us-gaap_DebtInstrumentAxis_f5eff12e-32ab-487c-88d8-4e9a68481720" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_f5eff12e-32ab-487c-88d8-4e9a68481720_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_f5eff12e-32ab-487c-88d8-4e9a68481720" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_f5eff12e-32ab-487c-88d8-4e9a68481720_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_6fb80a27-960f-4fd3-90bf-a3bec7af6341" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_f5eff12e-32ab-487c-88d8-4e9a68481720" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_6fb80a27-960f-4fd3-90bf-a3bec7af6341" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesMember_de90c053-d096-4928-bacd-978c67ddaae2" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_6fb80a27-960f-4fd3-90bf-a3bec7af6341" xlink:to="loc_htgc_SBADebenturesMember_de90c053-d096-4928-bacd-978c67ddaae2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JulyTwoThousandTwentyFourNotesMember_bdc1a7fa-77b5-48a2-8d58-52af9217a399" xlink:href="htgc-20240630.xsd#htgc_JulyTwoThousandTwentyFourNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_6fb80a27-960f-4fd3-90bf-a3bec7af6341" xlink:to="loc_htgc_JulyTwoThousandTwentyFourNotesMember_bdc1a7fa-77b5-48a2-8d58-52af9217a399" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_FebruaryTwoThousandTwentyFiveNotesMember_70eeef94-ede0-45e1-bcce-865e92ae7268" xlink:href="htgc-20240630.xsd#htgc_FebruaryTwoThousandTwentyFiveNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_6fb80a27-960f-4fd3-90bf-a3bec7af6341" xlink:to="loc_htgc_FebruaryTwoThousandTwentyFiveNotesMember_70eeef94-ede0-45e1-bcce-865e92ae7268" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JuneTwoThousandTwentyFiveNotesMember_6e4e8380-cfb4-429e-a279-3a491519ef1c" xlink:href="htgc-20240630.xsd#htgc_JuneTwoThousandTwentyFiveNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_6fb80a27-960f-4fd3-90bf-a3bec7af6341" xlink:to="loc_htgc_JuneTwoThousandTwentyFiveNotesMember_6e4e8380-cfb4-429e-a279-3a491519ef1c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JuneTwoThousandTwentyFiveThreeYearNotesMember_4af05ae8-26b1-455a-8b33-cb2be93828a4" xlink:href="htgc-20240630.xsd#htgc_JuneTwoThousandTwentyFiveThreeYearNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_6fb80a27-960f-4fd3-90bf-a3bec7af6341" xlink:to="loc_htgc_JuneTwoThousandTwentyFiveThreeYearNotesMember_4af05ae8-26b1-455a-8b33-cb2be93828a4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MarchTwoThousandTwentySixANotesMember_ca53867d-8fe3-4d33-bf1d-6572c4ecb67a" xlink:href="htgc-20240630.xsd#htgc_MarchTwoThousandTwentySixANotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_6fb80a27-960f-4fd3-90bf-a3bec7af6341" xlink:to="loc_htgc_MarchTwoThousandTwentySixANotesMember_ca53867d-8fe3-4d33-bf1d-6572c4ecb67a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MarchTwoThousandTwentySixBNotesMember_d8cb4c0d-46ef-4058-ba07-f995759203bf" xlink:href="htgc-20240630.xsd#htgc_MarchTwoThousandTwentySixBNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_6fb80a27-960f-4fd3-90bf-a3bec7af6341" xlink:to="loc_htgc_MarchTwoThousandTwentySixBNotesMember_d8cb4c0d-46ef-4058-ba07-f995759203bf" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TwoThousandThirtyOneAssetBackedNotesMember_f97b7e7e-cd16-44c4-b34b-2c9f728595fa" xlink:href="htgc-20240630.xsd#htgc_TwoThousandThirtyOneAssetBackedNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_6fb80a27-960f-4fd3-90bf-a3bec7af6341" xlink:to="loc_htgc_TwoThousandThirtyOneAssetBackedNotesMember_f97b7e7e-cd16-44c4-b34b-2c9f728595fa" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TwoThousandThirtyThreeNotesMember_96a624c7-218c-449d-943a-4e2ea46c13eb" xlink:href="htgc-20240630.xsd#htgc_TwoThousandThirtyThreeNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_6fb80a27-960f-4fd3-90bf-a3bec7af6341" xlink:to="loc_htgc_TwoThousandThirtyThreeNotesMember_96a624c7-218c-449d-943a-4e2ea46c13eb" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SeptemberTwoThousandTwentySixNotesMember_4ce0cf61-831a-4b6f-b17d-b123149cd162" xlink:href="htgc-20240630.xsd#htgc_SeptemberTwoThousandTwentySixNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_6fb80a27-960f-4fd3-90bf-a3bec7af6341" xlink:to="loc_htgc_SeptemberTwoThousandTwentySixNotesMember_4ce0cf61-831a-4b6f-b17d-b123149cd162" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JanuaryTwoThousandTwentySevenNotesMember_d9eb9dde-0a3b-4995-84fe-2967b7629424" xlink:href="htgc-20240630.xsd#htgc_JanuaryTwoThousandTwentySevenNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_6fb80a27-960f-4fd3-90bf-a3bec7af6341" xlink:to="loc_htgc_JanuaryTwoThousandTwentySevenNotesMember_d9eb9dde-0a3b-4995-84fe-2967b7629424" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityAxis_3c9ef21f-81e4-4971-a162-19b762d0a2a5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_htgc_CommitmentsAndContingenciesTable_4ea185c8-e080-4479-9fa6-85576350f4fb" xlink:to="loc_us-gaap_LineOfCreditFacilityAxis_3c9ef21f-81e4-4971-a162-19b762d0a2a5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLenderDomain_3c9ef21f-81e4-4971-a162-19b762d0a2a5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCreditFacilityLenderDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LineOfCreditFacilityAxis_3c9ef21f-81e4-4971-a162-19b762d0a2a5" xlink:to="loc_us-gaap_LineOfCreditFacilityLenderDomain_3c9ef21f-81e4-4971-a162-19b762d0a2a5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityLenderDomain_9c17ff53-e8ed-42f8-b53a-31ce2bae8d54" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCreditFacilityLenderDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LineOfCreditFacilityAxis_3c9ef21f-81e4-4971-a162-19b762d0a2a5" xlink:to="loc_us-gaap_LineOfCreditFacilityLenderDomain_9c17ff53-e8ed-42f8-b53a-31ce2bae8d54" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SMBCFacilityMember_29bcaab2-217c-4c99-8293-feeb5eaf0371" xlink:href="htgc-20240630.xsd#htgc_SMBCFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLenderDomain_9c17ff53-e8ed-42f8-b53a-31ce2bae8d54" xlink:to="loc_htgc_SMBCFacilityMember_29bcaab2-217c-4c99-8293-feeb5eaf0371" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MUFGBankFacilityMember_fdd99ab5-2ba7-4cae-a000-d5c3ceb53e36" xlink:href="htgc-20240630.xsd#htgc_MUFGBankFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LineOfCreditFacilityLenderDomain_9c17ff53-e8ed-42f8-b53a-31ce2bae8d54" xlink:to="loc_htgc_MUFGBankFacilityMember_fdd99ab5-2ba7-4cae-a000-d5c3ceb53e36" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtByMaturityAbstract_f7b161a0-9f2b-46cf-845f-f3862bd82ead" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebtByMaturityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_CommitmentsAndContingenciesLineItems_cb30ec9f-7b2b-464e-94df-46dfac8f4a8e" xlink:to="loc_us-gaap_LongTermDebtByMaturityAbstract_f7b161a0-9f2b-46cf-845f-f3862bd82ead" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_3bc84557-b8cd-462e-b4c3-3f46e43aaaf4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongTermDebtByMaturityAbstract_f7b161a0-9f2b-46cf-845f-f3862bd82ead" xlink:to="loc_us-gaap_LongTermDebt_3bc84557-b8cd-462e-b4c3-3f46e43aaaf4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_0c76d96d-0e7b-455e-842e-24c3ef0df1a2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongTermDebtByMaturityAbstract_f7b161a0-9f2b-46cf-845f-f3862bd82ead" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_0c76d96d-0e7b-455e-842e-24c3ef0df1a2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturingInYearsTwoAndThree_37b04efa-5fac-46b7-944a-7054be18274a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebtMaturingInYearsTwoAndThree"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongTermDebtByMaturityAbstract_f7b161a0-9f2b-46cf-845f-f3862bd82ead" xlink:to="loc_us-gaap_LongTermDebtMaturingInYearsTwoAndThree_37b04efa-5fac-46b7-944a-7054be18274a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturingInYearsFourAndFive_c2caef28-26b1-4dcc-b91c-f590b447ec61" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebtMaturingInYearsFourAndFive"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongTermDebtByMaturityAbstract_f7b161a0-9f2b-46cf-845f-f3862bd82ead" xlink:to="loc_us-gaap_LongTermDebtMaturingInYearsFourAndFive_c2caef28-26b1-4dcc-b91c-f590b447ec61" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive_8f5d6b8f-61a3-497f-9606-8e1c3512a176" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongTermDebtByMaturityAbstract_f7b161a0-9f2b-46cf-845f-f3862bd82ead" xlink:to="loc_us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive_8f5d6b8f-61a3-497f-9606-8e1c3512a176" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_31972cf4-e1e6-427c-8b72-329da1d26ff0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_CommitmentsAndContingenciesLineItems_cb30ec9f-7b2b-464e-94df-46dfac8f4a8e" xlink:to="loc_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_31972cf4-e1e6-427c-8b72-329da1d26ff0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_017b075b-63d5-404d-a07f-d4935dd86165" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_31972cf4-e1e6-427c-8b72-329da1d26ff0" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_017b075b-63d5-404d-a07f-d4935dd86165" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_75eb48bf-068c-4493-8089-be1977821355" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_31972cf4-e1e6-427c-8b72-329da1d26ff0" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_75eb48bf-068c-4493-8089-be1977821355" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_LesseeOperatingLeaseLiabilityToBePaidYearTwoAndThree_649b0368-a1c2-4306-9f14-f417b4dee5b1" xlink:href="htgc-20240630.xsd#htgc_LesseeOperatingLeaseLiabilityToBePaidYearTwoAndThree"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_31972cf4-e1e6-427c-8b72-329da1d26ff0" xlink:to="loc_htgc_LesseeOperatingLeaseLiabilityToBePaidYearTwoAndThree_649b0368-a1c2-4306-9f14-f417b4dee5b1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_LesseeOperatingLeaseLiabilityToBePaidYearFourAndFive_f4f3a0b8-6a47-4d6c-93d5-af7e94dc92c9" xlink:href="htgc-20240630.xsd#htgc_LesseeOperatingLeaseLiabilityToBePaidYearFourAndFive"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_31972cf4-e1e6-427c-8b72-329da1d26ff0" xlink:to="loc_htgc_LesseeOperatingLeaseLiabilityToBePaidYearFourAndFive_f4f3a0b8-6a47-4d6c-93d5-af7e94dc92c9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_3292a5bc-0fbe-425c-8d45-5de842976d82" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_31972cf4-e1e6-427c-8b72-329da1d26ff0" xlink:to="loc_us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_3292a5bc-0fbe-425c-8d45-5de842976d82" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractualObligationFiscalYearMaturityAbstract_71ddf892-df08-4f5d-bf17-b093f33a2ab4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ContractualObligationFiscalYearMaturityAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_CommitmentsAndContingenciesLineItems_cb30ec9f-7b2b-464e-94df-46dfac8f4a8e" xlink:to="loc_us-gaap_ContractualObligationFiscalYearMaturityAbstract_71ddf892-df08-4f5d-bf17-b093f33a2ab4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractualObligation_aacd3538-c8a3-44b2-b86a-45ca48e30416" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ContractualObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractualObligationFiscalYearMaturityAbstract_71ddf892-df08-4f5d-bf17-b093f33a2ab4" xlink:to="loc_us-gaap_ContractualObligation_aacd3538-c8a3-44b2-b86a-45ca48e30416" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractualObligationDueInNextTwelveMonths_7c531c1e-8d09-4fbf-af86-a8c0a2352cab" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ContractualObligationDueInNextTwelveMonths"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractualObligationFiscalYearMaturityAbstract_71ddf892-df08-4f5d-bf17-b093f33a2ab4" xlink:to="loc_us-gaap_ContractualObligationDueInNextTwelveMonths_7c531c1e-8d09-4fbf-af86-a8c0a2352cab" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractualObligationDueInSecondAndThirdYear_fcdea045-0b10-40c4-b64d-e36c5e1a1a6b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ContractualObligationDueInSecondAndThirdYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractualObligationFiscalYearMaturityAbstract_71ddf892-df08-4f5d-bf17-b093f33a2ab4" xlink:to="loc_us-gaap_ContractualObligationDueInSecondAndThirdYear_fcdea045-0b10-40c4-b64d-e36c5e1a1a6b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractualObligationDueInFourthAndFifthYear_1b1c2f26-38cd-4c3f-b540-82eb527f104a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ContractualObligationDueInFourthAndFifthYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractualObligationFiscalYearMaturityAbstract_71ddf892-df08-4f5d-bf17-b093f33a2ab4" xlink:to="loc_us-gaap_ContractualObligationDueInFourthAndFifthYear_1b1c2f26-38cd-4c3f-b540-82eb527f104a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractualObligationDueAfterFifthYear_854777d5-deb3-4836-ac0b-9c759cb08efd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ContractualObligationDueAfterFifthYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ContractualObligationFiscalYearMaturityAbstract_71ddf892-df08-4f5d-bf17-b093f33a2ab4" xlink:to="loc_us-gaap_ContractualObligationDueAfterFifthYear_854777d5-deb3-4836-ac0b-9c759cb08efd" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_838e1084-bec0-4247-a09b-2a2b2f542675" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_CommitmentsAndContingenciesLineItems_cb30ec9f-7b2b-464e-94df-46dfac8f4a8e" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_838e1084-bec0-4247-a09b-2a2b2f542675" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/RelatedPartyTransactionsNarrativeDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#RelatedPartyTransactionsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/RelatedPartyTransactionsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_a2f5b7e0-0564-4ded-9b78-69e3804b392c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_6b342177-7947-4fcd-8bcd-d93f7f307a5c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_a2f5b7e0-0564-4ded-9b78-69e3804b392c" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_6b342177-7947-4fcd-8bcd-d93f7f307a5c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_5d4d45f8-a96b-4667-a854-6697741d8613" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_6b342177-7947-4fcd-8bcd-d93f7f307a5c" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_5d4d45f8-a96b-4667-a854-6697741d8613" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_5d4d45f8-a96b-4667-a854-6697741d8613_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_5d4d45f8-a96b-4667-a854-6697741d8613" xlink:to="loc_us-gaap_RelatedPartyDomain_5d4d45f8-a96b-4667-a854-6697741d8613_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_dc54128c-93a6-449e-8dc9-be7df7cd276e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_5d4d45f8-a96b-4667-a854-6697741d8613" xlink:to="loc_us-gaap_RelatedPartyDomain_dc54128c-93a6-449e-8dc9-be7df7cd276e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_AdviserSubsidiaryMember_b4b78ecd-180d-433d-a975-007b35f316ea" xlink:href="htgc-20240630.xsd#htgc_AdviserSubsidiaryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_dc54128c-93a6-449e-8dc9-be7df7cd276e" xlink:to="loc_htgc_AdviserSubsidiaryMember_b4b78ecd-180d-433d-a975-007b35f316ea" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDividends_717ddffc-baf6-493b-bf83-9dd5bd34cd50" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsOfDividends"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_a2f5b7e0-0564-4ded-9b78-69e3804b392c" xlink:to="loc_us-gaap_PaymentsOfDividends_717ddffc-baf6-493b-bf83-9dd5bd34cd50" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionAmountsOfTransaction_63a74320-6ffa-420f-8623-37b3160d1525" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionAmountsOfTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_a2f5b7e0-0564-4ded-9b78-69e3804b392c" xlink:to="loc_us-gaap_RelatedPartyTransactionAmountsOfTransaction_63a74320-6ffa-420f-8623-37b3160d1525" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ReceivableFromRelatedParty_12e28feb-0a27-4574-ae1b-c9c2404ada7b" xlink:href="htgc-20240630.xsd#htgc_ReceivableFromRelatedParty"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_a2f5b7e0-0564-4ded-9b78-69e3804b392c" xlink:to="loc_htgc_ReceivableFromRelatedParty_12e28feb-0a27-4574-ae1b-c9c2404ada7b" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/RelatedPartyTransactionsScheduleofRelatedPartyTransactionsDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#RelatedPartyTransactionsScheduleofRelatedPartyTransactionsDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/RelatedPartyTransactionsScheduleofRelatedPartyTransactionsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_f716c917-4e2e-4cac-9795-82d5bec0b461" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_ffc2df84-ced3-47c3-a93c-0c52f8b2184f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_f716c917-4e2e-4cac-9795-82d5bec0b461" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_ffc2df84-ced3-47c3-a93c-0c52f8b2184f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_e1842f80-9b9d-426c-97ba-89e121b9f66d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_ffc2df84-ced3-47c3-a93c-0c52f8b2184f" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_e1842f80-9b9d-426c-97ba-89e121b9f66d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_e1842f80-9b9d-426c-97ba-89e121b9f66d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_e1842f80-9b9d-426c-97ba-89e121b9f66d" xlink:to="loc_us-gaap_RelatedPartyDomain_e1842f80-9b9d-426c-97ba-89e121b9f66d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_91d9c067-40af-43d6-9637-0afb94349a83" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_e1842f80-9b9d-426c-97ba-89e121b9f66d" xlink:to="loc_us-gaap_RelatedPartyDomain_91d9c067-40af-43d6-9637-0afb94349a83" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_AdviserFundsMember_e1c8084d-b8ad-4445-b362-9f3e9c89ef16" xlink:href="htgc-20240630.xsd#htgc_AdviserFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_91d9c067-40af-43d6-9637-0afb94349a83" xlink:to="loc_htgc_AdviserFundsMember_e1c8084d-b8ad-4445-b362-9f3e9c89ef16" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_AdviserSubsidiaryInvestmentCommitments_b002c0fa-4a5a-437f-840e-035f6a4404aa" xlink:href="htgc-20240630.xsd#htgc_AdviserSubsidiaryInvestmentCommitments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_f716c917-4e2e-4cac-9795-82d5bec0b461" xlink:to="loc_htgc_AdviserSubsidiaryInvestmentCommitments_b002c0fa-4a5a-437f-840e-035f6a4404aa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_AdviserSubsidiaryInvestmentFunding_29bbd60f-b78a-4597-bb6c-d311ccbf352d" xlink:href="htgc-20240630.xsd#htgc_AdviserSubsidiaryInvestmentFunding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_f716c917-4e2e-4cac-9795-82d5bec0b461" xlink:to="loc_htgc_AdviserSubsidiaryInvestmentFunding_29bbd60f-b78a-4597-bb6c-d311ccbf352d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionAmountsOfTransaction_6dfa3b1e-6bc3-48d7-bf15-cb5d31df2297" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RelatedPartyTransactionAmountsOfTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_f716c917-4e2e-4cac-9795-82d5bec0b461" xlink:to="loc_us-gaap_RelatedPartyTransactionAmountsOfTransaction_6dfa3b1e-6bc3-48d7-bf15-cb5d31df2297" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/SubsequentEventsDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#SubsequentEventsDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/SubsequentEventsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventLineItems_b04d9193-6276-4e85-bec6-13e70243635e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTable_e1e7dd0b-b4b9-4828-993c-d4fc7cbb00cd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems_b04d9193-6276-4e85-bec6-13e70243635e" xlink:to="loc_us-gaap_SubsequentEventTable_e1e7dd0b-b4b9-4828-993c-d4fc7cbb00cd" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsAxis_e51e8fe2-45ed-48f2-aaec-9d5546a49e6d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_e1e7dd0b-b4b9-4828-993c-d4fc7cbb00cd" xlink:to="loc_us-gaap_DividendsAxis_e51e8fe2-45ed-48f2-aaec-9d5546a49e6d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsDomain_e51e8fe2-45ed-48f2-aaec-9d5546a49e6d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DividendsAxis_e51e8fe2-45ed-48f2-aaec-9d5546a49e6d" xlink:to="loc_us-gaap_DividendsDomain_e51e8fe2-45ed-48f2-aaec-9d5546a49e6d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsDomain_596ccda6-ac50-4319-b8d8-6bced1ebaf72" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DividendsAxis_e51e8fe2-45ed-48f2-aaec-9d5546a49e6d" xlink:to="loc_us-gaap_DividendsDomain_596ccda6-ac50-4319-b8d8-6bced1ebaf72" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_BaseDividendMember_b65d8ade-b123-4ab1-9b1d-6fda21395d2d" xlink:href="htgc-20240630.xsd#htgc_BaseDividendMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DividendsDomain_596ccda6-ac50-4319-b8d8-6bced1ebaf72" xlink:to="loc_htgc_BaseDividendMember_b65d8ade-b123-4ab1-9b1d-6fda21395d2d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SupplementalDividendTotalMember_8466c6d8-ab18-40da-ab08-6ac4570321dd" xlink:href="htgc-20240630.xsd#htgc_SupplementalDividendTotalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DividendsDomain_596ccda6-ac50-4319-b8d8-6bced1ebaf72" xlink:to="loc_htgc_SupplementalDividendTotalMember_8466c6d8-ab18-40da-ab08-6ac4570321dd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SupplementalDividendMember_1be9c2d0-644d-4733-91a3-c8edf6cf655b" xlink:href="htgc-20240630.xsd#htgc_SupplementalDividendMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_SupplementalDividendTotalMember_8466c6d8-ab18-40da-ab08-6ac4570321dd" xlink:to="loc_htgc_SupplementalDividendMember_1be9c2d0-644d-4733-91a3-c8edf6cf655b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SupplementalDividendDeclaredMember_b30f7b68-c363-4b9e-8f71-a0e05272e2db" xlink:href="htgc-20240630.xsd#htgc_SupplementalDividendDeclaredMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_htgc_SupplementalDividendTotalMember_8466c6d8-ab18-40da-ab08-6ac4570321dd" xlink:to="loc_htgc_SupplementalDividendDeclaredMember_b30f7b68-c363-4b9e-8f71-a0e05272e2db" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_cc1474dd-6ce5-4295-9213-b90e9d6570c5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_e1e7dd0b-b4b9-4828-993c-d4fc7cbb00cd" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_cc1474dd-6ce5-4295-9213-b90e9d6570c5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_cc1474dd-6ce5-4295-9213-b90e9d6570c5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_cc1474dd-6ce5-4295-9213-b90e9d6570c5" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_cc1474dd-6ce5-4295-9213-b90e9d6570c5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_7ed0259e-fdb4-4bed-bb7f-c18acd71b2f2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_cc1474dd-6ce5-4295-9213-b90e9d6570c5" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_7ed0259e-fdb4-4bed-bb7f-c18acd71b2f2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_c5b482f4-f2dc-42d0-af90-5d0b7d882bab" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_7ed0259e-fdb4-4bed-bb7f-c18acd71b2f2" xlink:to="loc_us-gaap_SubsequentEventMember_c5b482f4-f2dc-42d0-af90-5d0b7d882bab" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_78bfa162-3bb8-4d12-a44f-87047c000e84" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_e1e7dd0b-b4b9-4828-993c-d4fc7cbb00cd" xlink:to="loc_us-gaap_DebtInstrumentAxis_78bfa162-3bb8-4d12-a44f-87047c000e84" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_78bfa162-3bb8-4d12-a44f-87047c000e84_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_78bfa162-3bb8-4d12-a44f-87047c000e84" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_78bfa162-3bb8-4d12-a44f-87047c000e84_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_3573b2c5-c289-4c99-ae66-1914cd481232" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_78bfa162-3bb8-4d12-a44f-87047c000e84" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_3573b2c5-c289-4c99-ae66-1914cd481232" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesMember_ce263a3c-6be7-4cfb-92f3-10e6b5587c97" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_3573b2c5-c289-4c99-ae66-1914cd481232" xlink:to="loc_htgc_SBADebenturesMember_ce263a3c-6be7-4cfb-92f3-10e6b5587c97" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JulyTwoThousandTwentyFourNotesMember_a7462b7b-dadd-4dc1-bcda-4f588b338f28" xlink:href="htgc-20240630.xsd#htgc_JulyTwoThousandTwentyFourNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_3573b2c5-c289-4c99-ae66-1914cd481232" xlink:to="loc_htgc_JulyTwoThousandTwentyFourNotesMember_a7462b7b-dadd-4dc1-bcda-4f588b338f28" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPayableAmountPerShare_34906140-7927-4576-b916-a49d3f21e671" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsPayableAmountPerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_b04d9193-6276-4e85-bec6-13e70243635e" xlink:to="loc_us-gaap_DividendsPayableAmountPerShare_34906140-7927-4576-b916-a49d3f21e671" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TotalSupplementalDividendsAmountToBePaidPerShare_941ace4c-962d-42aa-8da6-c666f83d8d94" xlink:href="htgc-20240630.xsd#htgc_TotalSupplementalDividendsAmountToBePaidPerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_b04d9193-6276-4e85-bec6-13e70243635e" xlink:to="loc_htgc_TotalSupplementalDividendsAmountToBePaidPerShare_941ace4c-962d-42aa-8da6-c666f83d8d94" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SupplementalDividendsAmountToBePaidEachQuarterPerShare_d78ed326-6558-4985-ac98-569f8b67be3f" xlink:href="htgc-20240630.xsd#htgc_SupplementalDividendsAmountToBePaidEachQuarterPerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_b04d9193-6276-4e85-bec6-13e70243635e" xlink:to="loc_htgc_SupplementalDividendsAmountToBePaidEachQuarterPerShare_d78ed326-6558-4985-ac98-569f8b67be3f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_2e75f572-60c1-43ec-b21f-1f5e1fef0188" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_b04d9193-6276-4e85-bec6-13e70243635e" xlink:to="loc_us-gaap_LongTermDebt_2e75f572-60c1-43ec-b21f-1f5e1fef0188" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBICLicenseTerm_7d3f83b2-5b07-4f39-a927-03f79157ef64" xlink:href="htgc-20240630.xsd#htgc_SBICLicenseTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_b04d9193-6276-4e85-bec6-13e70243635e" xlink:to="loc_htgc_SBICLicenseTerm_7d3f83b2-5b07-4f39-a927-03f79157ef64" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_94baf4eb-fb29-4c02-9d18-147ae3e18ad4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_b04d9193-6276-4e85-bec6-13e70243635e" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_94baf4eb-fb29-4c02-9d18-147ae3e18ad4" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfDebt_36b3cfe1-185f-4971-ac82-8df5ad394e94" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RepaymentsOfDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_b04d9193-6276-4e85-bec6-13e70243635e" xlink:to="loc_us-gaap_RepaymentsOfDebt_36b3cfe1-185f-4971-ac82-8df5ad394e94" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_RepaymentOfAccruedInterest_c1461426-4822-447f-9024-11f88474c104" xlink:href="htgc-20240630.xsd#htgc_RepaymentOfAccruedInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_b04d9193-6276-4e85-bec6-13e70243635e" xlink:to="loc_htgc_RepaymentOfAccruedInterest_c1461426-4822-447f-9024-11f88474c104" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/CONSOLIDATEDSCHEDULEOFINVESTMENTSINANDADVANCESTOAFFILIATESSummaryofscheduleofinvestmentDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#CONSOLIDATEDSCHEDULEOFINVESTMENTSINANDADVANCESTOAFFILIATESSummaryofscheduleofinvestmentDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/CONSOLIDATEDSCHEDULEOFINVESTMENTSINANDADVANCESTOAFFILIATESSummaryofscheduleofinvestmentDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesLineItems_8d29bb90-a87c-4bb9-933a-95e0305e2ad8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentsInAndAdvancesToAffiliatesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesTable_0b98457a-d6b9-48af-9bbb-490a265f18a6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentsInAndAdvancesToAffiliatesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesLineItems_8d29bb90-a87c-4bb9-933a-95e0305e2ad8" xlink:to="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesTable_0b98457a-d6b9-48af-9bbb-490a265f18a6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_34b435da-acba-4f21-b788-5e6a0f798195" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesTable_0b98457a-d6b9-48af-9bbb-490a265f18a6" xlink:to="loc_us-gaap_InvestmentTypeAxis_34b435da-acba-4f21-b788-5e6a0f798195" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_34b435da-acba-4f21-b788-5e6a0f798195_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_34b435da-acba-4f21-b788-5e6a0f798195" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_34b435da-acba-4f21-b788-5e6a0f798195_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_55b204a7-7be1-45a5-948e-b832ac762145" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_34b435da-acba-4f21-b788-5e6a0f798195" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_55b204a7-7be1-45a5-948e-b832ac762145" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnsecuredDebtMember_2611b462-0b1d-4a7e-9344-39469d907d18" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnsecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_55b204a7-7be1-45a5-948e-b832ac762145" xlink:to="loc_us-gaap_UnsecuredDebtMember_2611b462-0b1d-4a7e-9344-39469d907d18" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SeniorSecuredDebtMember_84d2f0e6-28ad-407d-8ce4-eb48a9c5d839" xlink:href="htgc-20240630.xsd#htgc_SeniorSecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_55b204a7-7be1-45a5-948e-b832ac762145" xlink:to="loc_htgc_SeniorSecuredDebtMember_84d2f0e6-28ad-407d-8ce4-eb48a9c5d839" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_86763c97-21b3-4170-8d01-912e1864c7e5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesTable_0b98457a-d6b9-48af-9bbb-490a265f18a6" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_86763c97-21b3-4170-8d01-912e1864c7e5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_86763c97-21b3-4170-8d01-912e1864c7e5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_86763c97-21b3-4170-8d01-912e1864c7e5" xlink:to="loc_us-gaap_EquityComponentDomain_86763c97-21b3-4170-8d01-912e1864c7e5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_9a04cf9b-a6d4-46ef-a140-bec33021f12c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_86763c97-21b3-4170-8d01-912e1864c7e5" xlink:to="loc_us-gaap_EquityComponentDomain_9a04cf9b-a6d4-46ef-a140-bec33021f12c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockMember_cebb6729-3358-44c4-bf1f-8ce040288c48" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_9a04cf9b-a6d4-46ef-a140-bec33021f12c" xlink:to="loc_us-gaap_PreferredStockMember_cebb6729-3358-44c4-bf1f-8ce040288c48" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_c81513c2-b203-4110-b994-5ea20883ae9d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_9a04cf9b-a6d4-46ef-a140-bec33021f12c" xlink:to="loc_us-gaap_CommonStockMember_c81513c2-b203-4110-b994-5ea20883ae9d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MemberUnitsMember_9d7bae17-248c-4f75-a89a-ef4e32e04dbe" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MemberUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_9a04cf9b-a6d4-46ef-a140-bec33021f12c" xlink:to="loc_us-gaap_MemberUnitsMember_9d7bae17-248c-4f75-a89a-ef4e32e04dbe" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_c1af7e84-5f76-4d60-b94d-0e5a6a95853b" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesTable_0b98457a-d6b9-48af-9bbb-490a265f18a6" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_c1af7e84-5f76-4d60-b94d-0e5a6a95853b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_c1af7e84-5f76-4d60-b94d-0e5a6a95853b_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_c1af7e84-5f76-4d60-b94d-0e5a6a95853b" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_c1af7e84-5f76-4d60-b94d-0e5a6a95853b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_58060c9b-f426-43d5-8c4e-5757f841eefb" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_c1af7e84-5f76-4d60-b94d-0e5a6a95853b" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_58060c9b-f426-43d5-8c4e-5757f841eefb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CoronadoAestheticsLLCMember_ec5743a8-1328-407b-8fac-7417b43da220" xlink:href="htgc-20240630.xsd#htgc_CoronadoAestheticsLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_58060c9b-f426-43d5-8c4e-5757f841eefb" xlink:to="loc_htgc_CoronadoAestheticsLLCMember_ec5743a8-1328-407b-8fac-7417b43da220" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_GibraltarAcquisitionLLCMember_2a7cace7-10a3-444d-a6b6-d06fdedadf68" xlink:href="htgc-20240630.xsd#htgc_GibraltarAcquisitionLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_58060c9b-f426-43d5-8c4e-5757f841eefb" xlink:to="loc_htgc_GibraltarAcquisitionLLCMember_2a7cace7-10a3-444d-a6b6-d06fdedadf68" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_HerculesAdviserLLCMember_774d305f-ef1f-4731-afdb-9bc22f1645fa" xlink:href="htgc-20240630.xsd#htgc_HerculesAdviserLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_58060c9b-f426-43d5-8c4e-5757f841eefb" xlink:to="loc_htgc_HerculesAdviserLLCMember_774d305f-ef1f-4731-afdb-9bc22f1645fa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TecturaCorporationMember_5b568a61-3691-447a-b08f-1b25641ed9a1" xlink:href="htgc-20240630.xsd#htgc_TecturaCorporationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_58060c9b-f426-43d5-8c4e-5757f841eefb" xlink:to="loc_htgc_TecturaCorporationMember_5b568a61-3691-447a-b08f-1b25641ed9a1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationAxis_11de5390-12d0-4582-b145-5b9c331e8252" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentIssuerAffiliationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesTable_0b98457a-d6b9-48af-9bbb-490a265f18a6" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationAxis_11de5390-12d0-4582-b145-5b9c331e8252" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_11de5390-12d0-4582-b145-5b9c331e8252_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_11de5390-12d0-4582-b145-5b9c331e8252" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_11de5390-12d0-4582-b145-5b9c331e8252_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_a49fb487-50a9-4c6a-893e-7c27c0595f37" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_11de5390-12d0-4582-b145-5b9c331e8252" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_a49fb487-50a9-4c6a-893e-7c27c0595f37" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentAffiliatedIssuerControlledMember_e649d525-b577-49c9-9831-5b9645734ec5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentAffiliatedIssuerControlledMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationDomain_a49fb487-50a9-4c6a-893e-7c27c0595f37" xlink:to="loc_us-gaap_InvestmentAffiliatedIssuerControlledMember_e649d525-b577-49c9-9831-5b9645734ec5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_83ce3359-6075-4f96-9075-d9829fb7fd50" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesTable_0b98457a-d6b9-48af-9bbb-490a265f18a6" xlink:to="loc_srt_StatementGeographicalAxis_83ce3359-6075-4f96-9075-d9829fb7fd50" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_83ce3359-6075-4f96-9075-d9829fb7fd50_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_83ce3359-6075-4f96-9075-d9829fb7fd50" xlink:to="loc_srt_SegmentGeographicalDomain_83ce3359-6075-4f96-9075-d9829fb7fd50_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_2037e167-9727-4d22-a455-07d62bfea153" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_83ce3359-6075-4f96-9075-d9829fb7fd50" xlink:to="loc_srt_SegmentGeographicalDomain_2037e167-9727-4d22-a455-07d62bfea153" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MajorityOwnedControlInvestmentsMember_c5a176fe-e4a8-480e-8f88-eda3723a08dc" xlink:href="htgc-20240630.xsd#htgc_MajorityOwnedControlInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_2037e167-9727-4d22-a455-07d62bfea153" xlink:to="loc_htgc_MajorityOwnedControlInvestmentsMember_c5a176fe-e4a8-480e-8f88-eda3723a08dc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_OtherControlInvestmentsMember_73a7381a-16b0-4ac6-9d93-6b2f449021d3" xlink:href="htgc-20240630.xsd#htgc_OtherControlInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_2037e167-9727-4d22-a455-07d62bfea153" xlink:to="loc_htgc_OtherControlInvestmentsMember_73a7381a-16b0-4ac6-9d93-6b2f449021d3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossInvestmentIncomeOperating_2e6d596b-21b9-49b9-bab6-6f9fe1578032" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GrossInvestmentIncomeOperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesLineItems_8d29bb90-a87c-4bb9-933a-95e0305e2ad8" xlink:to="loc_us-gaap_GrossInvestmentIncomeOperating_2e6d596b-21b9-49b9-bab6-6f9fe1578032" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealizedInvestmentGainsLosses_2566ff47-bc6d-49bc-9c9b-bbfa0d22d62d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RealizedInvestmentGainsLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesLineItems_8d29bb90-a87c-4bb9-933a-95e0305e2ad8" xlink:to="loc_us-gaap_RealizedInvestmentGainsLosses_2566ff47-bc6d-49bc-9c9b-bbfa0d22d62d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtFairValue_c928e99e-72c6-4821-8a36-2dfe72f44bc4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesLineItems_8d29bb90-a87c-4bb9-933a-95e0305e2ad8" xlink:to="loc_us-gaap_InvestmentOwnedAtFairValue_c928e99e-72c6-4821-8a36-2dfe72f44bc4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_GrossCAAdditions_36efe701-cf88-4968-9c4f-c9151089ddd4" xlink:href="htgc-20240630.xsd#htgc_GrossCAAdditions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesLineItems_8d29bb90-a87c-4bb9-933a-95e0305e2ad8" xlink:to="loc_htgc_GrossCAAdditions_36efe701-cf88-4968-9c4f-c9151089ddd4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_GrossCaReduction_2c8b686c-91a0-4393-b688-b59f84b3bcdb" xlink:href="htgc-20240630.xsd#htgc_GrossCaReduction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesLineItems_8d29bb90-a87c-4bb9-933a-95e0305e2ad8" xlink:to="loc_htgc_GrossCaReduction_2c8b686c-91a0-4393-b688-b59f84b3bcdb" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossOnInvestments_b73289ea-e3e6-4b44-a4cd-ce6637777ceb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnrealizedGainLossOnInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesLineItems_8d29bb90-a87c-4bb9-933a-95e0305e2ad8" xlink:to="loc_us-gaap_UnrealizedGainLossOnInvestments_b73289ea-e3e6-4b44-a4cd-ce6637777ceb" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtFairValue_60fd061c-3c20-4780-bc93-e5f7007f2eda" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedAtFairValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.htgc.com/role/CONSOLIDATEDSCHEDULEOFINVESTMENTSINANDADVANCESTOAFFILIATESSummaryofscheduleofinvestmentParentheticalDetails" xlink:type="simple" xlink:href="htgc-20240630.xsd#CONSOLIDATEDSCHEDULEOFINVESTMENTSINANDADVANCESTOAFFILIATESSummaryofscheduleofinvestmentParentheticalDetails"/>
  <link:definitionLink xlink:role="http://www.htgc.com/role/CONSOLIDATEDSCHEDULEOFINVESTMENTSINANDADVANCESTOAFFILIATESSummaryofscheduleofinvestmentParentheticalDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesLineItems_a6019ccf-96ae-40ec-90d2-1c16375abbac" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentsInAndAdvancesToAffiliatesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesTable_a738bc93-0b74-4948-86b1-9f7b3440bff0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentsInAndAdvancesToAffiliatesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesLineItems_a6019ccf-96ae-40ec-90d2-1c16375abbac" xlink:to="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesTable_a738bc93-0b74-4948-86b1-9f7b3440bff0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationAxis_118102b3-8fe3-4c46-bb1b-6d1c45c79b73" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentIssuerAffiliationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesTable_a738bc93-0b74-4948-86b1-9f7b3440bff0" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationAxis_118102b3-8fe3-4c46-bb1b-6d1c45c79b73" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_118102b3-8fe3-4c46-bb1b-6d1c45c79b73_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_118102b3-8fe3-4c46-bb1b-6d1c45c79b73" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_118102b3-8fe3-4c46-bb1b-6d1c45c79b73_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIssuerAffiliationDomain_9fd912b7-27cb-41e9-abaf-fd8e8d154ee1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentIssuerAffiliationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationAxis_118102b3-8fe3-4c46-bb1b-6d1c45c79b73" xlink:to="loc_us-gaap_InvestmentIssuerAffiliationDomain_9fd912b7-27cb-41e9-abaf-fd8e8d154ee1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentAffiliatedIssuerControlledMember_a46f64c6-f651-4d34-b939-5229866ace63" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentAffiliatedIssuerControlledMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentIssuerAffiliationDomain_9fd912b7-27cb-41e9-abaf-fd8e8d154ee1" xlink:to="loc_us-gaap_InvestmentAffiliatedIssuerControlledMember_a46f64c6-f651-4d34-b939-5229866ace63" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_652c7fd1-e7c6-4b78-b6be-086e8fddb6af" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesTable_a738bc93-0b74-4948-86b1-9f7b3440bff0" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_652c7fd1-e7c6-4b78-b6be-086e8fddb6af" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_652c7fd1-e7c6-4b78-b6be-086e8fddb6af_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_652c7fd1-e7c6-4b78-b6be-086e8fddb6af" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_652c7fd1-e7c6-4b78-b6be-086e8fddb6af_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_7d5c316f-6036-492f-b79b-8d049f11cfa0" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_652c7fd1-e7c6-4b78-b6be-086e8fddb6af" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_7d5c316f-6036-492f-b79b-8d049f11cfa0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CoronadoAestheticsLLCMember_98ea7945-92dd-4272-bc5c-df77f3ca5877" xlink:href="htgc-20240630.xsd#htgc_CoronadoAestheticsLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_7d5c316f-6036-492f-b79b-8d049f11cfa0" xlink:to="loc_htgc_CoronadoAestheticsLLCMember_98ea7945-92dd-4272-bc5c-df77f3ca5877" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_GibraltarAcquisitionLLCMember_57cff0f2-2972-4f2e-a22d-b4dbeea17687" xlink:href="htgc-20240630.xsd#htgc_GibraltarAcquisitionLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_7d5c316f-6036-492f-b79b-8d049f11cfa0" xlink:to="loc_htgc_GibraltarAcquisitionLLCMember_57cff0f2-2972-4f2e-a22d-b4dbeea17687" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_HerculesAdviserLLCMember_d0665e85-514d-46c6-9f7b-b4e42094b418" xlink:href="htgc-20240630.xsd#htgc_HerculesAdviserLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_7d5c316f-6036-492f-b79b-8d049f11cfa0" xlink:to="loc_htgc_HerculesAdviserLLCMember_d0665e85-514d-46c6-9f7b-b4e42094b418" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TecturaCorporationMember_b170aba3-fffa-47d1-ae9e-0c4db0f580bd" xlink:href="htgc-20240630.xsd#htgc_TecturaCorporationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_7d5c316f-6036-492f-b79b-8d049f11cfa0" xlink:to="loc_htgc_TecturaCorporationMember_b170aba3-fffa-47d1-ae9e-0c4db0f580bd" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesByIndustryAxis_33ac6cdb-f30a-458b-85d3-481cd25ee98f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquitySecuritiesByIndustryAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesTable_a738bc93-0b74-4948-86b1-9f7b3440bff0" xlink:to="loc_us-gaap_EquitySecuritiesByIndustryAxis_33ac6cdb-f30a-458b-85d3-481cd25ee98f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesIndustryMember_33ac6cdb-f30a-458b-85d3-481cd25ee98f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquitySecuritiesIndustryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_EquitySecuritiesByIndustryAxis_33ac6cdb-f30a-458b-85d3-481cd25ee98f" xlink:to="loc_us-gaap_EquitySecuritiesIndustryMember_33ac6cdb-f30a-458b-85d3-481cd25ee98f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesIndustryMember_5a1dc782-0940-4e10-8f75-9df46b56fa08" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquitySecuritiesIndustryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_EquitySecuritiesByIndustryAxis_33ac6cdb-f30a-458b-85d3-481cd25ee98f" xlink:to="loc_us-gaap_EquitySecuritiesIndustryMember_5a1dc782-0940-4e10-8f75-9df46b56fa08" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MedicalDevicesAndEquipmentMember_b3beb7cb-8334-4538-ab35-7c491cd8bcf3" xlink:href="htgc-20240630.xsd#htgc_MedicalDevicesAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesIndustryMember_5a1dc782-0940-4e10-8f75-9df46b56fa08" xlink:to="loc_htgc_MedicalDevicesAndEquipmentMember_b3beb7cb-8334-4538-ab35-7c491cd8bcf3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_DiversifiedFinancialServicesMember_30132af9-cdec-4b1c-ab7e-d868a368cc0e" xlink:href="htgc-20240630.xsd#htgc_DiversifiedFinancialServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesIndustryMember_5a1dc782-0940-4e10-8f75-9df46b56fa08" xlink:to="loc_htgc_DiversifiedFinancialServicesMember_30132af9-cdec-4b1c-ab7e-d868a368cc0e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ConsumerAndBusinessServicesMember_85d3b9b3-554f-48b0-86cf-9111bc7b0a61" xlink:href="htgc-20240630.xsd#htgc_ConsumerAndBusinessServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquitySecuritiesIndustryMember_5a1dc782-0940-4e10-8f75-9df46b56fa08" xlink:to="loc_htgc_ConsumerAndBusinessServicesMember_85d3b9b3-554f-48b0-86cf-9111bc7b0a61" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_3188787e-567a-4a77-800b-16a2932dc058" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesTable_a738bc93-0b74-4948-86b1-9f7b3440bff0" xlink:to="loc_us-gaap_StatementClassOfStockAxis_3188787e-567a-4a77-800b-16a2932dc058" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_3188787e-567a-4a77-800b-16a2932dc058_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_3188787e-567a-4a77-800b-16a2932dc058" xlink:to="loc_us-gaap_ClassOfStockDomain_3188787e-567a-4a77-800b-16a2932dc058_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_8682e4cc-57fb-4352-bd9d-54f48e90ed56" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_3188787e-567a-4a77-800b-16a2932dc058" xlink:to="loc_us-gaap_ClassOfStockDomain_8682e4cc-57fb-4352-bd9d-54f48e90ed56" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesAPreferredStockMember_c72f3ea7-8557-4b3d-aea7-0bd28453c508" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SeriesAPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_8682e4cc-57fb-4352-bd9d-54f48e90ed56" xlink:to="loc_us-gaap_SeriesAPreferredStockMember_c72f3ea7-8557-4b3d-aea7-0bd28453c508" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_PreferredSeriesBBMember_1c698a17-bc1a-4ec4-abfe-53ae8229c8bc" xlink:href="htgc-20240630.xsd#htgc_PreferredSeriesBBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_8682e4cc-57fb-4352-bd9d-54f48e90ed56" xlink:to="loc_htgc_PreferredSeriesBBMember_1c698a17-bc1a-4ec4-abfe-53ae8229c8bc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesCPreferredStockMember_a0f2af4b-d5af-4440-8b30-de3449a5ac34" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SeriesCPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_8682e4cc-57fb-4352-bd9d-54f48e90ed56" xlink:to="loc_us-gaap_SeriesCPreferredStockMember_a0f2af4b-d5af-4440-8b30-de3449a5ac34" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_671918e4-3327-4843-9a5f-31629f56694f" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesTable_a738bc93-0b74-4948-86b1-9f7b3440bff0" xlink:to="loc_srt_StatementGeographicalAxis_671918e4-3327-4843-9a5f-31629f56694f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_671918e4-3327-4843-9a5f-31629f56694f_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_671918e4-3327-4843-9a5f-31629f56694f" xlink:to="loc_srt_SegmentGeographicalDomain_671918e4-3327-4843-9a5f-31629f56694f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_3f83220f-a0c9-4ed8-b0d0-e1fb3ae060be" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_671918e4-3327-4843-9a5f-31629f56694f" xlink:to="loc_srt_SegmentGeographicalDomain_3f83220f-a0c9-4ed8-b0d0-e1fb3ae060be" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MajorityOwnedControlInvestmentsMember_f99d4383-6769-4647-99f0-7b13cdd56fc5" xlink:href="htgc-20240630.xsd#htgc_MajorityOwnedControlInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_3f83220f-a0c9-4ed8-b0d0-e1fb3ae060be" xlink:to="loc_htgc_MajorityOwnedControlInvestmentsMember_f99d4383-6769-4647-99f0-7b13cdd56fc5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_OtherControlInvestmentsMember_439f1754-b37c-457d-8dc2-5dacaacb3784" xlink:href="htgc-20240630.xsd#htgc_OtherControlInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_3f83220f-a0c9-4ed8-b0d0-e1fb3ae060be" xlink:to="loc_htgc_OtherControlInvestmentsMember_439f1754-b37c-457d-8dc2-5dacaacb3784" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_cdfc74f7-f7f5-4bec-bde7-1c4b8a11024c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesTable_a738bc93-0b74-4948-86b1-9f7b3440bff0" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_cdfc74f7-f7f5-4bec-bde7-1c4b8a11024c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_cdfc74f7-f7f5-4bec-bde7-1c4b8a11024c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_cdfc74f7-f7f5-4bec-bde7-1c4b8a11024c" xlink:to="loc_us-gaap_EquityComponentDomain_cdfc74f7-f7f5-4bec-bde7-1c4b8a11024c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_23ec1fd6-68a5-4686-aaad-4c5cbf59ea73" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_cdfc74f7-f7f5-4bec-bde7-1c4b8a11024c" xlink:to="loc_us-gaap_EquityComponentDomain_23ec1fd6-68a5-4686-aaad-4c5cbf59ea73" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockMember_69b4f47d-2bad-43c2-acf5-2142e3f7d4c0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_23ec1fd6-68a5-4686-aaad-4c5cbf59ea73" xlink:to="loc_us-gaap_PreferredStockMember_69b4f47d-2bad-43c2-acf5-2142e3f7d4c0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_4394eb49-169f-4f46-827a-21d0930d7e38" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_23ec1fd6-68a5-4686-aaad-4c5cbf59ea73" xlink:to="loc_us-gaap_CommonStockMember_4394eb49-169f-4f46-827a-21d0930d7e38" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MemberUnitsMember_32d9801a-a59a-4148-ba7b-89d798d4bf4c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MemberUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_23ec1fd6-68a5-4686-aaad-4c5cbf59ea73" xlink:to="loc_us-gaap_MemberUnitsMember_32d9801a-a59a-4148-ba7b-89d798d4bf4c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_5e3519db-3fe6-4db2-9766-fd730e3742dd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesTable_a738bc93-0b74-4948-86b1-9f7b3440bff0" xlink:to="loc_us-gaap_InvestmentTypeAxis_5e3519db-3fe6-4db2-9766-fd730e3742dd" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_5e3519db-3fe6-4db2-9766-fd730e3742dd_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_5e3519db-3fe6-4db2-9766-fd730e3742dd" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_5e3519db-3fe6-4db2-9766-fd730e3742dd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_ae0b5d1a-b331-4217-bcba-c163fe1c2937" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_5e3519db-3fe6-4db2-9766-fd730e3742dd" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_ae0b5d1a-b331-4217-bcba-c163fe1c2937" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnsecuredDebtMember_64e87058-3bbe-4b99-a3af-a7ba5b9cdfb1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnsecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_ae0b5d1a-b331-4217-bcba-c163fe1c2937" xlink:to="loc_us-gaap_UnsecuredDebtMember_64e87058-3bbe-4b99-a3af-a7ba5b9cdfb1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_UnsecuredDebtOneMember_d4bd9f62-62f9-4e4f-b19c-43cae66e1f38" xlink:href="htgc-20240630.xsd#htgc_UnsecuredDebtOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_ae0b5d1a-b331-4217-bcba-c163fe1c2937" xlink:to="loc_htgc_UnsecuredDebtOneMember_d4bd9f62-62f9-4e4f-b19c-43cae66e1f38" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_UnsecuredDebtTwoMember_93d15be8-d0e3-45b1-9066-6730aef7f885" xlink:href="htgc-20240630.xsd#htgc_UnsecuredDebtTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_ae0b5d1a-b331-4217-bcba-c163fe1c2937" xlink:to="loc_htgc_UnsecuredDebtTwoMember_93d15be8-d0e3-45b1-9066-6730aef7f885" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SeniorSecuredDebtMember_2db4e4cd-5785-4030-8e5d-5e86feb25222" xlink:href="htgc-20240630.xsd#htgc_SeniorSecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_ae0b5d1a-b331-4217-bcba-c163fe1c2937" xlink:to="loc_htgc_SeniorSecuredDebtMember_2db4e4cd-5785-4030-8e5d-5e86feb25222" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedPercentOfNetAssets_b5e4ba85-8064-439d-95dd-e724b62b704d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedPercentOfNetAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesLineItems_a6019ccf-96ae-40ec-90d2-1c16375abbac" xlink:to="loc_us-gaap_InvestmentOwnedPercentOfNetAssets_b5e4ba85-8064-439d-95dd-e724b62b704d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_InvestmentsMaturityMonthAndYear_624c9054-b540-487f-9965-ebdf40d0170c" xlink:href="htgc-20240630.xsd#htgc_InvestmentsMaturityMonthAndYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesLineItems_a6019ccf-96ae-40ec-90d2-1c16375abbac" xlink:to="loc_htgc_InvestmentsMaturityMonthAndYear_624c9054-b540-487f-9965-ebdf40d0170c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentInterestRatePaidInCash_713a2306-3c3b-4d92-ab5f-6c65f5d24bd7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentInterestRatePaidInCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesLineItems_a6019ccf-96ae-40ec-90d2-1c16375abbac" xlink:to="loc_us-gaap_InvestmentInterestRatePaidInCash_713a2306-3c3b-4d92-ab5f-6c65f5d24bd7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentInterestRatePaidInKind_07c0ba75-e5b0-4673-b70d-fb2956c47ae7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentInterestRatePaidInKind"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesLineItems_a6019ccf-96ae-40ec-90d2-1c16375abbac" xlink:to="loc_us-gaap_InvestmentInterestRatePaidInKind_07c0ba75-e5b0-4673-b70d-fb2956c47ae7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedBalanceShares_ec2bf755-2e0a-4c90-aa71-c0d64ddc0bf3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedBalanceShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesLineItems_a6019ccf-96ae-40ec-90d2-1c16375abbac" xlink:to="loc_us-gaap_InvestmentOwnedBalanceShares_ec2bf755-2e0a-4c90-aa71-c0d64ddc0bf3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedBalancePrincipalAmount_89e06f18-3079-4841-812b-9bd76bda59eb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedBalancePrincipalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesLineItems_a6019ccf-96ae-40ec-90d2-1c16375abbac" xlink:to="loc_us-gaap_InvestmentOwnedBalancePrincipalAmount_89e06f18-3079-4841-812b-9bd76bda59eb" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtCost_ebe9a4b4-c84a-4dbb-839f-49b5ade7c581" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedAtCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesLineItems_a6019ccf-96ae-40ec-90d2-1c16375abbac" xlink:to="loc_us-gaap_InvestmentOwnedAtCost_ebe9a4b4-c84a-4dbb-839f-49b5ade7c581" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtFairValue_87b1ab33-ba54-4c28-a83a-ab3b5d560657" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InvestmentOwnedAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsInAndAdvancesToAffiliatesLineItems_a6019ccf-96ae-40ec-90d2-1c16375abbac" xlink:to="loc_us-gaap_InvestmentOwnedAtFairValue_87b1ab33-ba54-4c28-a83a-ab3b5d560657" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://xbrl.sec.gov/ecd/AwardTypeOnly" xlink:type="simple" xlink:href="https://xbrl.sec.gov/ecd/2024/ecd-2024.xsd#AwardTypeOnly"/>
  <link:definitionLink xlink:role="http://xbrl.sec.gov/ecd/AwardTypeOnly" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_us-gaap_CommonStockMember" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ServiceVestingAwardsMember_7a1b67eb-efb0-4fea-b562-04521e8b5de4" xlink:href="htgc-20240630.xsd#htgc_ServiceVestingAwardsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_htgc_ServiceVestingAwardsMember_7a1b67eb-efb0-4fea-b562-04521e8b5de4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_PerformanceVestingAwardsMember_ff9e3ad6-6377-48f4-a426-8489787e6749" xlink:href="htgc-20240630.xsd#htgc_PerformanceVestingAwardsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_htgc_PerformanceVestingAwardsMember_ff9e3ad6-6377-48f4-a426-8489787e6749" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_PerformanceDeuMember_7303bfb7-96fa-4964-bec9-6c048f298ecb" xlink:href="htgc-20240630.xsd#htgc_PerformanceDeuMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_htgc_PerformanceDeuMember_7303bfb7-96fa-4964-bec9-6c048f298ecb" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_LiabilityClassifiedAwardsMember_ce08a5e3-5d99-40fb-be21-6a287b85c07d" xlink:href="htgc-20240630.xsd#htgc_LiabilityClassifiedAwardsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_htgc_LiabilityClassifiedAwardsMember_ce08a5e3-5d99-40fb-be21-6a287b85c07d" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_OtherLiabilityClassifiedAwardsMember_b0cbeac5-6e05-45b7-8256-0ccd2460697d" xlink:href="htgc-20240630.xsd#htgc_OtherLiabilityClassifiedAwardsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="loc_htgc_OtherLiabilityClassifiedAwardsMember_b0cbeac5-6e05-45b7-8256-0ccd2460697d" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://xbrl.sec.gov/cef/role/SecurityOnly" xlink:type="simple" xlink:href="https://xbrl.sec.gov/cef/2024/cef-2024.xsd#SecurityOnly"/>
  <link:definitionLink xlink:role="http://xbrl.sec.gov/cef/role/SecurityOnly" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfStockDomain"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CommonStockParValueZeroPointZeroZeroOnePerShareMember_805f67e6-bb42-4517-a17a-85150150e653" xlink:href="htgc-20240630.xsd#htgc_CommonStockParValueZeroPointZeroZeroOnePerShareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain" xlink:to="loc_htgc_CommonStockParValueZeroPointZeroZeroOnePerShareMember_805f67e6-bb42-4517-a17a-85150150e653" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SixPointTwoFiveNotesDueTwoThousandThirtyThreeMember_3c071a27-5df8-4ae9-b639-19cbf3d882d6" xlink:href="htgc-20240630.xsd#htgc_SixPointTwoFiveNotesDueTwoThousandThirtyThreeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain" xlink:to="loc_htgc_SixPointTwoFiveNotesDueTwoThousandThirtyThreeMember_3c071a27-5df8-4ae9-b639-19cbf3d882d6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CommonGrossProceedsMember_1dfa6414-1628-4de2-9a88-65d30a0039e7" xlink:href="htgc-20240630.xsd#htgc_CommonGrossProceedsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain" xlink:to="loc_htgc_CommonGrossProceedsMember_1dfa6414-1628-4de2-9a88-65d30a0039e7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_CommonOfferingExpensesMember_87e1d004-04b3-4177-afa3-ea004d69481d" xlink:href="htgc-20240630.xsd#htgc_CommonOfferingExpensesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain" xlink:to="loc_htgc_CommonOfferingExpensesMember_87e1d004-04b3-4177-afa3-ea004d69481d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SpilloveramountpershareMember_3b487b69-6769-4f39-92a6-9ffe8099060a" xlink:href="htgc-20240630.xsd#htgc_SpilloveramountpershareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain" xlink:to="loc_htgc_SpilloveramountpershareMember_3b487b69-6769-4f39-92a6-9ffe8099060a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesAPreferredStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SeriesAPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain" xlink:to="loc_us-gaap_SeriesAPreferredStockMember" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_PreferredSeriesBBMember_069bee6f-6d7d-443e-a8b4-d9ae971837c8" xlink:href="htgc-20240630.xsd#htgc_PreferredSeriesBBMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain" xlink:to="loc_htgc_PreferredSeriesBBMember_069bee6f-6d7d-443e-a8b4-d9ae971837c8" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesCPreferredStockMember" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SeriesCPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain" xlink:to="loc_us-gaap_SeriesCPreferredStockMember" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_PromissoryNotesMember_1b55b253-4d15-4497-ae81-85cb3b7039f6" xlink:href="htgc-20240630.xsd#htgc_PromissoryNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="loc_htgc_PromissoryNotesMember_1b55b253-4d15-4497-ae81-85cb3b7039f6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesMember_3542015e-1580-4091-a78a-7848a14ffcf8" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="loc_htgc_SBADebenturesMember_3542015e-1580-4091-a78a-7848a14ffcf8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JulyTwoThousandTwentyFourNotesMember_f2a8d15c-60d3-420f-ab26-72f2883f8174" xlink:href="htgc-20240630.xsd#htgc_JulyTwoThousandTwentyFourNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="loc_htgc_JulyTwoThousandTwentyFourNotesMember_f2a8d15c-60d3-420f-ab26-72f2883f8174" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_FebruaryTwoThousandTwentyFiveNotesMember_99c1d990-23bf-4d1c-b834-93bcee8ca253" xlink:href="htgc-20240630.xsd#htgc_FebruaryTwoThousandTwentyFiveNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="loc_htgc_FebruaryTwoThousandTwentyFiveNotesMember_99c1d990-23bf-4d1c-b834-93bcee8ca253" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JuneTwoThousandTwentyFiveNotesMember_ec1da07b-7f7d-40a3-b79d-40b3dfdf058c" xlink:href="htgc-20240630.xsd#htgc_JuneTwoThousandTwentyFiveNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="loc_htgc_JuneTwoThousandTwentyFiveNotesMember_ec1da07b-7f7d-40a3-b79d-40b3dfdf058c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JuneTwoThousandTwentyFiveThreeYearNotesMember_2211fa17-4b7e-4740-80f6-919cc7f2769b" xlink:href="htgc-20240630.xsd#htgc_JuneTwoThousandTwentyFiveThreeYearNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="loc_htgc_JuneTwoThousandTwentyFiveThreeYearNotesMember_2211fa17-4b7e-4740-80f6-919cc7f2769b" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MarchTwoThousandTwentySixANotesMember_bd37f326-7c3c-4c26-b807-02176f5c1b9e" xlink:href="htgc-20240630.xsd#htgc_MarchTwoThousandTwentySixANotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="loc_htgc_MarchTwoThousandTwentySixANotesMember_bd37f326-7c3c-4c26-b807-02176f5c1b9e" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MarchTwoThousandTwentySixBNotesMember_82217780-a569-4775-a065-a6aa263a9d28" xlink:href="htgc-20240630.xsd#htgc_MarchTwoThousandTwentySixBNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="loc_htgc_MarchTwoThousandTwentySixBNotesMember_82217780-a569-4775-a065-a6aa263a9d28" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SeptemberTwoThousandTwentySixNotesMember_b15abb6f-94fc-4056-b9bd-19f9d06ef4e7" xlink:href="htgc-20240630.xsd#htgc_SeptemberTwoThousandTwentySixNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="loc_htgc_SeptemberTwoThousandTwentySixNotesMember_b15abb6f-94fc-4056-b9bd-19f9d06ef4e7" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_JanuaryTwoThousandTwentySevenNotesMember_6a3e5417-1027-4100-ba9a-66c7d4cc01dd" xlink:href="htgc-20240630.xsd#htgc_JanuaryTwoThousandTwentySevenNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="loc_htgc_JanuaryTwoThousandTwentySevenNotesMember_6a3e5417-1027-4100-ba9a-66c7d4cc01dd" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TwoThousandThirtyOneAssetBackedNotesMember_2d525a54-4975-4f3a-a494-dc51a31e332f" xlink:href="htgc-20240630.xsd#htgc_TwoThousandThirtyOneAssetBackedNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="loc_htgc_TwoThousandThirtyOneAssetBackedNotesMember_2d525a54-4975-4f3a-a494-dc51a31e332f" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_TwoThousandThirtyThreeNotesMember_3e7f8774-8b94-4bc1-a1b1-0196891aa7ad" xlink:href="htgc-20240630.xsd#htgc_TwoThousandThirtyThreeNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="loc_htgc_TwoThousandThirtyThreeNotesMember_3e7f8774-8b94-4bc1-a1b1-0196891aa7ad" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_MUFGBankFacilityMember_31766183-4fbc-4227-a60c-320e4238b773" xlink:href="htgc-20240630.xsd#htgc_MUFGBankFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="loc_htgc_MUFGBankFacilityMember_31766183-4fbc-4227-a60c-320e4238b773" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SMBCFacilityMember_cfc62d8b-0d76-483a-8962-72c325b2cc7d" xlink:href="htgc-20240630.xsd#htgc_SMBCFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="loc_htgc_SMBCFacilityMember_cfc62d8b-0d76-483a-8962-72c325b2cc7d" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesIssuedOnMarchTwentySixTwoThousandAndTwentyOneMember_a7b3d3f9-7488-4c38-83b2-12539bd261f2" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesIssuedOnMarchTwentySixTwoThousandAndTwentyOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="loc_htgc_SBADebenturesIssuedOnMarchTwentySixTwoThousandAndTwentyOneMember_a7b3d3f9-7488-4c38-83b2-12539bd261f2" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesIssuedOnJuneTwentyFiveTwoThousandAndTwentyOneMember_5eeb74b8-c7b5-40ab-a3cc-2b2bc1701f74" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesIssuedOnJuneTwentyFiveTwoThousandAndTwentyOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="loc_htgc_SBADebenturesIssuedOnJuneTwentyFiveTwoThousandAndTwentyOneMember_5eeb74b8-c7b5-40ab-a3cc-2b2bc1701f74" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesIssuedOnJulyTwentyEightTwoThousandAndTwentyOneMember_d74e6710-356a-45a3-a6fb-8bb62ba5cefc" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesIssuedOnJulyTwentyEightTwoThousandAndTwentyOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="loc_htgc_SBADebenturesIssuedOnJulyTwentyEightTwoThousandAndTwentyOneMember_d74e6710-356a-45a3-a6fb-8bb62ba5cefc" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesIssuedOnAugustTwentyTwoThousandAndTwentyOneMember_77a809ea-1191-4c28-b260-3238475fbb07" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesIssuedOnAugustTwentyTwoThousandAndTwentyOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="loc_htgc_SBADebenturesIssuedOnAugustTwentyTwoThousandAndTwentyOneMember_77a809ea-1191-4c28-b260-3238475fbb07" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesIssuedOnOctoberTwentyOneTwoThousandAndTwentyOneMember_82dd166c-288e-4133-9c02-f5316cc0a121" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesIssuedOnOctoberTwentyOneTwoThousandAndTwentyOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="loc_htgc_SBADebenturesIssuedOnOctoberTwentyOneTwoThousandAndTwentyOneMember_82dd166c-288e-4133-9c02-f5316cc0a121" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesIssuedOnNovemberOneTwoThousandAndTwentyOneMember_45d62409-5c16-400a-83cc-e30fe27c2ba4" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesIssuedOnNovemberOneTwoThousandAndTwentyOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="loc_htgc_SBADebenturesIssuedOnNovemberOneTwoThousandAndTwentyOneMember_45d62409-5c16-400a-83cc-e30fe27c2ba4" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesIssuedOnNovemberFifteenTwoThousandAndTwentyOneMember_b89823e0-4da5-4096-87c0-d18cd06e1b5b" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesIssuedOnNovemberFifteenTwoThousandAndTwentyOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="loc_htgc_SBADebenturesIssuedOnNovemberFifteenTwoThousandAndTwentyOneMember_b89823e0-4da5-4096-87c0-d18cd06e1b5b" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesIssuedOnNovemberThirtyTwoThousandAndTwentyOneMember_18c90560-b3f8-4f78-a011-b5fda5e3b963" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesIssuedOnNovemberThirtyTwoThousandAndTwentyOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="loc_htgc_SBADebenturesIssuedOnNovemberThirtyTwoThousandAndTwentyOneMember_18c90560-b3f8-4f78-a011-b5fda5e3b963" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesIssuedOnDecemberTwentyTwoThousandAndTwentyOneMember_dfcb419c-cfc1-41ce-b560-7ac24813ee4d" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesIssuedOnDecemberTwentyTwoThousandAndTwentyOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="loc_htgc_SBADebenturesIssuedOnDecemberTwentyTwoThousandAndTwentyOneMember_dfcb419c-cfc1-41ce-b560-7ac24813ee4d" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesIssuedOnDecemberTwentyThreeTwoThousandAndTwentyOneMember_5ce8d291-3960-45d4-bbcc-afaa71b789ca" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesIssuedOnDecemberTwentyThreeTwoThousandAndTwentyOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="loc_htgc_SBADebenturesIssuedOnDecemberTwentyThreeTwoThousandAndTwentyOneMember_5ce8d291-3960-45d4-bbcc-afaa71b789ca" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesIssuedOnDecemberTwentyEightTwoThousandAndTwentyOneMember_aa131b7b-d60e-44db-8bd1-3eac3c708747" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesIssuedOnDecemberTwentyEightTwoThousandAndTwentyOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="loc_htgc_SBADebenturesIssuedOnDecemberTwentyEightTwoThousandAndTwentyOneMember_aa131b7b-d60e-44db-8bd1-3eac3c708747" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesIssuedOnJanuaryFourteenTwoThousandAndTwentyTwoMember_e14e9249-e073-45ca-ab66-c2e4400c6011" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesIssuedOnJanuaryFourteenTwoThousandAndTwentyTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="loc_htgc_SBADebenturesIssuedOnJanuaryFourteenTwoThousandAndTwentyTwoMember_e14e9249-e073-45ca-ab66-c2e4400c6011" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SBADebenturesIssuedOnJanuaryTwentyOneTwoThousandAndTwentyTwoMember_2c78c709-3be9-4a4b-9b5c-a1b111762ff5" xlink:href="htgc-20240630.xsd#htgc_SBADebenturesIssuedOnJanuaryTwentyOneTwoThousandAndTwentyTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain" xlink:to="loc_htgc_SBADebenturesIssuedOnJanuaryTwentyOneTwoThousandAndTwentyTwoMember_2c78c709-3be9-4a4b-9b5c-a1b111762ff5" xlink:type="arc" order="27"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://xbrl.sec.gov/ecd/role/IndividualsOnly" xlink:type="simple" xlink:href="https://xbrl.sec.gov/ecd/2024/ecd-2024.xsd#IndividualsOnly"/>
  <link:definitionLink xlink:role="http://xbrl.sec.gov/ecd/role/IndividualsOnly" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_ecd_AllIndividualsMember" xlink:href="https://xbrl.sec.gov/ecd/2024/ecd-2024.xsd#ecd_AllIndividualsMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_ScottBluesteinMember_a0f9a0f2-f2a8-4aeb-ad7e-448e0c4627d0" xlink:href="htgc-20240630.xsd#htgc_ScottBluesteinMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_ecd_AllIndividualsMember" xlink:to="loc_htgc_ScottBluesteinMember_a0f9a0f2-f2a8-4aeb-ad7e-448e0c4627d0" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://xbrl.sec.gov/cef/role/RiskOnly" xlink:type="simple" xlink:href="https://xbrl.sec.gov/cef/2024/cef-2024.xsd#RiskOnly"/>
  <link:definitionLink xlink:role="http://xbrl.sec.gov/cef/role/RiskOnly" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_cef_AllRisksMember" xlink:href="https://xbrl.sec.gov/cef/2024/cef-2024.xsd#cef_AllRisksMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_SignificantPortfolioInvestmentMember_d3620a35-d345-403e-8eb4-97275326074e" xlink:href="htgc-20240630.xsd#htgc_SignificantPortfolioInvestmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_cef_AllRisksMember" xlink:to="loc_htgc_SignificantPortfolioInvestmentMember_d3620a35-d345-403e-8eb4-97275326074e" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists" xlink:type="simple" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-roles-2024.xsd#eedm"/>
  <link:definitionLink xlink:role="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_VariableRateDomain"/>
    <link:loc xlink:type="locator" xlink:label="loc_htgc_OneMonthSecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember_e3ad3c8c-8d49-43b7-8bd9-5dc701b2a471" xlink:href="htgc-20240630.xsd#htgc_OneMonthSecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain" xlink:to="loc_htgc_OneMonthSecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember_e3ad3c8c-8d49-43b7-8bd9-5dc701b2a471" xlink:type="arc" order="1"/>
  </link:definitionLink>
</link:linkbase>
