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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:dac6a9f9-eead-4b76-ad95-baedb2c7b0c0,g:b120eb99-6ebe-45ba-93cd-9c21dbd65dec-->
<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.criteo.com/role/Coverpage" xlink:type="simple" xlink:href="crto-20251231.xsd#Coverpage"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/Coverpage" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationTable_44e003cc-c1f0-4cfd-8256-a7491da64f39" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentInformationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_DocumentInformationTable_44e003cc-c1f0-4cfd-8256-a7491da64f39" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_4ad49cd7-dd2f-4c3b-b99a-8903e974cd19" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_DocumentInformationTable_44e003cc-c1f0-4cfd-8256-a7491da64f39" xlink:to="loc_us-gaap_StatementClassOfStockAxis_4ad49cd7-dd2f-4c3b-b99a-8903e974cd19" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_4ad49cd7-dd2f-4c3b-b99a-8903e974cd19_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_4ad49cd7-dd2f-4c3b-b99a-8903e974cd19" xlink:to="loc_us-gaap_ClassOfStockDomain_4ad49cd7-dd2f-4c3b-b99a-8903e974cd19_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_f40cbd3e-823d-4315-be51-f921521b2c75" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_4ad49cd7-dd2f-4c3b-b99a-8903e974cd19" xlink:to="loc_us-gaap_ClassOfStockDomain_f40cbd3e-823d-4315-be51-f921521b2c75" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_AmericanDepositarySharesMember_a55ba55e-a124-4ea1-91bb-f393a75c38b6" xlink:href="crto-20251231.xsd#crto_AmericanDepositarySharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_f40cbd3e-823d-4315-be51-f921521b2c75" xlink:to="loc_crto_AmericanDepositarySharesMember_a55ba55e-a124-4ea1-91bb-f393a75c38b6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_dbfabbec-3049-4f67-977c-0bf378d67f56" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_f40cbd3e-823d-4315-be51-f921521b2c75" xlink:to="loc_us-gaap_CommonStockMember_dbfabbec-3049-4f67-977c-0bf378d67f56" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_d1d1c170-c49d-41c8-a496-36aedae82c20" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentType"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_DocumentType_d1d1c170-c49d-41c8-a496-36aedae82c20" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentAnnualReport_5b727d2c-0fdd-44df-b675-3bb50c03d337" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentAnnualReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_DocumentAnnualReport_5b727d2c-0fdd-44df-b675-3bb50c03d337" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_d3347a52-77ed-4530-86c9-36455e10029e" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentPeriodEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_DocumentPeriodEndDate_d3347a52-77ed-4530-86c9-36455e10029e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CurrentFiscalYearEndDate_f139a4b6-23e0-44ec-8a78-abc10ff03ca2" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CurrentFiscalYearEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_CurrentFiscalYearEndDate_f139a4b6-23e0-44ec-8a78-abc10ff03ca2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentTransitionReport_0867a3dc-7c37-463d-a247-653fe2bc80c1" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentTransitionReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_DocumentTransitionReport_0867a3dc-7c37-463d-a247-653fe2bc80c1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_4eab6943-20f4-4617-a796-c9a9e6f6a387" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityFileNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_EntityFileNumber_4eab6943-20f4-4617-a796-c9a9e6f6a387" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_a01e8dac-56da-4d74-a674-20f8b18d3ed4" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityRegistrantName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_EntityRegistrantName_a01e8dac-56da-4d74-a674-20f8b18d3ed4" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_781db2bd-3a38-470f-a55a-e621dced6eb4" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_EntityIncorporationStateCountryCode_781db2bd-3a38-470f-a55a-e621dced6eb4" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_b97cd403-0d3b-4238-9069-3e56a9bd24ed" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressAddressLine1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_EntityAddressAddressLine1_b97cd403-0d3b-4238-9069-3e56a9bd24ed" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_ee1f01eb-3661-41c8-9d6e-f7044a206074" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressCityOrTown"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_EntityAddressCityOrTown_ee1f01eb-3661-41c8-9d6e-f7044a206074" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCountry_c2ad388b-8af6-41f7-a636-693e0c90b562" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressCountry"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_EntityAddressCountry_c2ad388b-8af6-41f7-a636-693e0c90b562" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_7bdcff40-7899-40e0-8e97-74dec237dccc" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressPostalZipCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_EntityAddressPostalZipCode_7bdcff40-7899-40e0-8e97-74dec237dccc" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CountryRegion_91cc3f89-6730-4bc5-a451-59d54f619b1f" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CountryRegion"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_CountryRegion_91cc3f89-6730-4bc5-a451-59d54f619b1f" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_abf6252e-f9e4-49a4-a8ee-58be9a177815" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CityAreaCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_CityAreaCode_abf6252e-f9e4-49a4-a8ee-58be9a177815" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_310b7f19-cc9e-463e-9103-484cf472f515" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LocalPhoneNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_LocalPhoneNumber_310b7f19-cc9e-463e-9103-484cf472f515" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_f9a51b38-b73d-473a-8b20-942a1218e467" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_Security12bTitle"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_Security12bTitle_f9a51b38-b73d-473a-8b20-942a1218e467" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_3ee4ad91-1f13-493c-b2e5-5e508a250838" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_TradingSymbol"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_TradingSymbol_3ee4ad91-1f13-493c-b2e5-5e508a250838" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_db7e5f80-a6e1-4918-8f03-cfc6e0d051e3" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_SecurityExchangeName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_SecurityExchangeName_db7e5f80-a6e1-4918-8f03-cfc6e0d051e3" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityWellKnownSeasonedIssuer_30c1ae60-c42b-441c-b4e8-d937f2e0c504" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityWellKnownSeasonedIssuer"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_EntityWellKnownSeasonedIssuer_30c1ae60-c42b-441c-b4e8-d937f2e0c504" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityVoluntaryFilers_f9c4c6b8-9967-406b-ad0b-259ebc7763aa" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityVoluntaryFilers"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_EntityVoluntaryFilers_f9c4c6b8-9967-406b-ad0b-259ebc7763aa" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCurrentReportingStatus_09a20246-6e33-4c3d-9dbf-c952bc4aa5a5" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCurrentReportingStatus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_EntityCurrentReportingStatus_09a20246-6e33-4c3d-9dbf-c952bc4aa5a5" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInteractiveDataCurrent_5a0bac9f-47c7-4f09-ba7a-a31a7e45659d" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityInteractiveDataCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_EntityInteractiveDataCurrent_5a0bac9f-47c7-4f09-ba7a-a31a7e45659d" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFilerCategory_b305a2e2-a83c-4238-9639-f70463a1aa60" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityFilerCategory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_EntityFilerCategory_b305a2e2-a83c-4238-9639-f70463a1aa60" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitySmallBusiness_809df5bc-3acc-4116-b93c-8a1a800c2abc" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntitySmallBusiness"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_EntitySmallBusiness_809df5bc-3acc-4116-b93c-8a1a800c2abc" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_adc14377-b219-4553-b898-a822537b2d5d" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_EntityEmergingGrowthCompany_adc14377-b219-4553-b898-a822537b2d5d" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_IcfrAuditorAttestationFlag_76574be6-cdab-40e9-989a-3a0f8b9b7490" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_IcfrAuditorAttestationFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_IcfrAuditorAttestationFlag_76574be6-cdab-40e9-989a-3a0f8b9b7490" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFinStmtErrorCorrectionFlag_6e8a54f1-fa16-4673-8e52-38f9b494a08c" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentFinStmtErrorCorrectionFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_DocumentFinStmtErrorCorrectionFlag_6e8a54f1-fa16-4673-8e52-38f9b494a08c" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityShellCompany_5914644b-0a79-4acd-ae25-402780f4dc15" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityShellCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_EntityShellCompany_5914644b-0a79-4acd-ae25-402780f4dc15" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityPublicFloat_407a4f3c-3bfc-4d0f-98aa-7f189f85cf7e" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityPublicFloat"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_EntityPublicFloat_407a4f3c-3bfc-4d0f-98aa-7f189f85cf7e" xlink:type="arc" order="28"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCommonStockSharesOutstanding_f66395de-5eec-4e67-a684-9403ed910dc9" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_EntityCommonStockSharesOutstanding_f66395de-5eec-4e67-a684-9403ed910dc9" xlink:type="arc" order="29"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_4199b741-1314-4f5e-b354-2f7403379b63" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCentralIndexKey"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_EntityCentralIndexKey_4199b741-1314-4f5e-b354-2f7403379b63" xlink:type="arc" order="30"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalYearFocus_a080128c-212f-4729-89c2-f98f61486376" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentFiscalYearFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_DocumentFiscalYearFocus_a080128c-212f-4729-89c2-f98f61486376" xlink:type="arc" order="31"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalPeriodFocus_2de138f7-d31d-47a8-8987-1497d0b4a5fa" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentFiscalPeriodFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_DocumentFiscalPeriodFocus_2de138f7-d31d-47a8-8987-1497d0b4a5fa" xlink:type="arc" order="32"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_89207255-733f-4644-98d6-8354483affd0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_AmendmentFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_AmendmentFlag_89207255-733f-4644-98d6-8354483affd0" xlink:type="arc" order="33"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_NoTradingSymbolFlag_ea9481c3-0a35-4648-8c36-07153ab1cd25" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_NoTradingSymbolFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_NoTradingSymbolFlag_ea9481c3-0a35-4648-8c36-07153ab1cd25" xlink:type="arc" order="34"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentsIncorporatedByReferenceTextBlock_019b8d88-24e0-7623-8e31-04b1f55c3197" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentsIncorporatedByReferenceTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_f2f906d8-3b10-4e66-93a1-3be48ceef237" xlink:to="loc_dei_DocumentsIncorporatedByReferenceTextBlock_019b8d88-24e0-7623-8e31-04b1f55c3197" xlink:type="arc" order="35"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/ConsolidatedStatementsofChangesinShareholdersEquity" xlink:type="simple" xlink:href="crto-20251231.xsd#ConsolidatedStatementsofChangesinShareholdersEquity"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/ConsolidatedStatementsofChangesinShareholdersEquity" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_c9b72d5d-2853-498b-a276-d81bf040bea0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_c28c4de8-80e1-4ae5-844a-95825c8fafc3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_c9b72d5d-2853-498b-a276-d81bf040bea0" xlink:to="loc_us-gaap_StatementTable_c28c4de8-80e1-4ae5-844a-95825c8fafc3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_d94dd478-90a4-4b35-8bbc-d3f15230a2a0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_c28c4de8-80e1-4ae5-844a-95825c8fafc3" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_d94dd478-90a4-4b35-8bbc-d3f15230a2a0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_d94dd478-90a4-4b35-8bbc-d3f15230a2a0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_d94dd478-90a4-4b35-8bbc-d3f15230a2a0" xlink:to="loc_us-gaap_EquityComponentDomain_d94dd478-90a4-4b35-8bbc-d3f15230a2a0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_08f9f534-0051-4a31-bbda-5ab960566875" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_d94dd478-90a4-4b35-8bbc-d3f15230a2a0" xlink:to="loc_us-gaap_EquityComponentDomain_08f9f534-0051-4a31-bbda-5ab960566875" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ParentMember_8064b069-2683-44e7-b82d-34369506cce4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_08f9f534-0051-4a31-bbda-5ab960566875" xlink:to="loc_us-gaap_ParentMember_8064b069-2683-44e7-b82d-34369506cce4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_00d5f5d8-40fb-474f-92f6-47fc53d817b8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_8064b069-2683-44e7-b82d-34369506cce4" xlink:to="loc_us-gaap_CommonStockMember_00d5f5d8-40fb-474f-92f6-47fc53d817b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonMember_3e5862a6-0153-46c9-87ad-f80743cd1e6b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockCommonMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_8064b069-2683-44e7-b82d-34369506cce4" xlink:to="loc_us-gaap_TreasuryStockCommonMember_3e5862a6-0153-46c9-87ad-f80743cd1e6b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_644cb588-f074-4bc8-b9c5-fb72e9d5478b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_8064b069-2683-44e7-b82d-34369506cce4" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_644cb588-f074-4bc8-b9c5-fb72e9d5478b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_d8e78930-ad5a-4aa1-845c-c6991a5d2de0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_8064b069-2683-44e7-b82d-34369506cce4" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_d8e78930-ad5a-4aa1-845c-c6991a5d2de0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_42a27019-9728-48ea-80f3-c84d7aacff89" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ParentMember_8064b069-2683-44e7-b82d-34369506cce4" xlink:to="loc_us-gaap_RetainedEarningsMember_42a27019-9728-48ea-80f3-c84d7aacff89" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestMember_ae9668ec-f957-43e3-a7d5-44fc67883b03" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_08f9f534-0051-4a31-bbda-5ab960566875" xlink:to="loc_us-gaap_NoncontrollingInterestMember_ae9668ec-f957-43e3-a7d5-44fc67883b03" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ef75a521-433f-44ee-8372-15497cefce90" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_c9b72d5d-2853-498b-a276-d81bf040bea0" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ef75a521-433f-44ee-8372-15497cefce90" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesOutstanding_cc5006a1-ac3d-49b1-9ef3-fa6e013b6ea8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ef75a521-433f-44ee-8372-15497cefce90" xlink:to="loc_us-gaap_SharesOutstanding_cc5006a1-ac3d-49b1-9ef3-fa6e013b6ea8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_004c6734-786b-4923-8a8b-90712774f085" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ef75a521-433f-44ee-8372-15497cefce90" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_004c6734-786b-4923-8a8b-90712774f085" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonShares_933b9486-c33b-4d1d-a35d-c75a0522a3f5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockCommonShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ef75a521-433f-44ee-8372-15497cefce90" xlink:to="loc_us-gaap_TreasuryStockCommonShares_933b9486-c33b-4d1d-a35d-c75a0522a3f5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_cebf8397-0067-4b5f-9560-c849371f81ba" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ef75a521-433f-44ee-8372-15497cefce90" xlink:to="loc_us-gaap_ProfitLoss_cebf8397-0067-4b5f-9560-c849371f81ba" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_2a97acf6-ab9e-4bc8-88fe-51311adb010c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ef75a521-433f-44ee-8372-15497cefce90" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_2a97acf6-ab9e-4bc8-88fe-51311adb010c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_e8bb866c-5e8f-4e32-9cc3-61b81b30f5a9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ef75a521-433f-44ee-8372-15497cefce90" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_e8bb866c-5e8f-4e32-9cc3-61b81b30f5a9" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_7dcf9662-05a8-414d-ac45-81e2951528b7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ef75a521-433f-44ee-8372-15497cefce90" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueNewIssues_7dcf9662-05a8-414d-ac45-81e2951528b7" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_d6d7973d-c1e4-4d61-96c4-af093a407aea" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockSharesAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ef75a521-433f-44ee-8372-15497cefce90" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_d6d7973d-c1e4-4d61-96c4-af093a407aea" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_21a390f8-1bff-4210-9233-7fdb8711f0c1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ef75a521-433f-44ee-8372-15497cefce90" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_21a390f8-1bff-4210-9233-7fdb8711f0c1" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_096df863-bb2d-4fb4-a425-febf20e43f9a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ef75a521-433f-44ee-8372-15497cefce90" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_096df863-bb2d-4fb4-a425-febf20e43f9a" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityOther_7e58c458-e8eb-4d7d-ad59-a02922778107" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_ef75a521-433f-44ee-8372-15497cefce90" xlink:to="loc_us-gaap_StockholdersEquityOther_7e58c458-e8eb-4d7d-ad59-a02922778107" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesOutstanding_fd8be053-6c7f-40cc-b719-53e3462fffc1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_095e6639-3050-49af-99a2-5d918d707e94" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonShares_0af4f85b-eaee-410e-9cf9-b6dd11680bbc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockCommonShares"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/ConsolidatedStatementsofChangesinShareholdersEquityParenthetical" xlink:type="simple" xlink:href="crto-20251231.xsd#ConsolidatedStatementsofChangesinShareholdersEquityParenthetical"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/ConsolidatedStatementsofChangesinShareholdersEquityParenthetical" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_c2e5b787-6296-423f-9791-746e84908f47" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_d2ed26cf-1f15-4866-8372-aa0be029e8ec" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_c2e5b787-6296-423f-9791-746e84908f47" xlink:to="loc_us-gaap_StatementTable_d2ed26cf-1f15-4866-8372-aa0be029e8ec" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_7a521493-b3c6-4b8b-970d-822397b313ef" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_d2ed26cf-1f15-4866-8372-aa0be029e8ec" xlink:to="loc_us-gaap_AwardTypeAxis_7a521493-b3c6-4b8b-970d-822397b313ef" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7a521493-b3c6-4b8b-970d-822397b313ef_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_7a521493-b3c6-4b8b-970d-822397b313ef" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7a521493-b3c6-4b8b-970d-822397b313ef_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_ff80d949-fc35-4274-a724-199ddc17931b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_7a521493-b3c6-4b8b-970d-822397b313ef" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_ff80d949-fc35-4274-a724-199ddc17931b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_105f8934-e7fa-4049-8948-52a704115e0d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_ff80d949-fc35-4274-a724-199ddc17931b" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_105f8934-e7fa-4049-8948-52a704115e0d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_LockUpSharesLUSsMember_9eb86c89-d68c-401e-a0a8-23299fa8cd01" xlink:href="crto-20251231.xsd#crto_LockUpSharesLUSsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_ff80d949-fc35-4274-a724-199ddc17931b" xlink:to="loc_crto_LockUpSharesLUSsMember_9eb86c89-d68c-401e-a0a8-23299fa8cd01" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StockRepurchaseProgramAuthorizedAmount1_3fcc4a20-6cc7-445a-9708-677333d44046" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_StockRepurchaseProgramAuthorizedAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_c2e5b787-6296-423f-9791-746e84908f47" xlink:to="loc_srt_StockRepurchaseProgramAuthorizedAmount1_3fcc4a20-6cc7-445a-9708-677333d44046" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_b568a16b-77d3-444a-b8e5-0f9dbed12b62" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockSharesAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_c2e5b787-6296-423f-9791-746e84908f47" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_b568a16b-77d3-444a-b8e5-0f9dbed12b62" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockAcquiredAverageCostPerShare_1be24758-ac85-4b74-94fb-3b63627167d2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockAcquiredAverageCostPerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_c2e5b787-6296-423f-9791-746e84908f47" xlink:to="loc_us-gaap_TreasuryStockAcquiredAverageCostPerShare_1be24758-ac85-4b74-94fb-3b63627167d2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_44c505a3-4071-414c-80ab-c26548b8121d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_c2e5b787-6296-423f-9791-746e84908f47" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_44c505a3-4071-414c-80ab-c26548b8121d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_4e81fd11-a632-403a-98a4-2cb73174cee6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_c2e5b787-6296-423f-9791-746e84908f47" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_4e81fd11-a632-403a-98a4-2cb73174cee6" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/PrinciplesandAccountingMethodsScheduleofConsolidationsDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#PrinciplesandAccountingMethodsScheduleofConsolidationsDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/PrinciplesandAccountingMethodsScheduleofConsolidationsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentsLineItems_d828ea6e-28bf-46b1-807f-eb1b07184729" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfInvestmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentsTable_1bf47e1a-f0e9-49c1-a8e0-6ee244a9f027" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfInvestmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_d828ea6e-28bf-46b1-807f-eb1b07184729" xlink:to="loc_us-gaap_ScheduleOfInvestmentsTable_1bf47e1a-f0e9-49c1-a8e0-6ee244a9f027" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_068368cc-6f94-497a-9b9a-5cb3b4ddc7bd" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentsTable_1bf47e1a-f0e9-49c1-a8e0-6ee244a9f027" xlink:to="loc_srt_ConsolidatedEntitiesAxis_068368cc-6f94-497a-9b9a-5cb3b4ddc7bd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_068368cc-6f94-497a-9b9a-5cb3b4ddc7bd_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_068368cc-6f94-497a-9b9a-5cb3b4ddc7bd" xlink:to="loc_srt_ConsolidatedEntitiesDomain_068368cc-6f94-497a-9b9a-5cb3b4ddc7bd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_e3d2bdd7-29e6-455d-ada1-c31f1e5b10d2" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_068368cc-6f94-497a-9b9a-5cb3b4ddc7bd" xlink:to="loc_srt_ConsolidatedEntitiesDomain_e3d2bdd7-29e6-455d-ada1-c31f1e5b10d2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ParentCompanyMember_bee47554-07f4-4bd3-9771-bdd0ef081008" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ParentCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_e3d2bdd7-29e6-455d-ada1-c31f1e5b10d2" xlink:to="loc_srt_ParentCompanyMember_bee47554-07f4-4bd3-9771-bdd0ef081008" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_20f6f1cb-39e4-47f2-aea1-23db4ca10761" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentsTable_1bf47e1a-f0e9-49c1-a8e0-6ee244a9f027" xlink:to="loc_dei_LegalEntityAxis_20f6f1cb-39e4-47f2-aea1-23db4ca10761" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_20f6f1cb-39e4-47f2-aea1-23db4ca10761_default" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_20f6f1cb-39e4-47f2-aea1-23db4ca10761" xlink:to="loc_dei_EntityDomain_20f6f1cb-39e4-47f2-aea1-23db4ca10761_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_20f6f1cb-39e4-47f2-aea1-23db4ca10761" xlink:to="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoFranceSASFranceMember_777c4100-7992-46a0-9008-7c21f98bed7f" xlink:href="crto-20251231.xsd#crto_CriteoFranceSASFranceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_CriteoFranceSASFranceMember_777c4100-7992-46a0-9008-7c21f98bed7f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoTechnologySASMember_d94e906a-d69d-4df8-89c3-6751b1d4c960" xlink:href="crto-20251231.xsd#crto_CriteoTechnologySASMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_CriteoTechnologySASMember_d94e906a-d69d-4df8-89c3-6751b1d4c960" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoHoldingsInc.Member_70949588-c56e-4392-bfb7-e3627644b3b4" xlink:href="crto-20251231.xsd#crto_CriteoHoldingsInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_CriteoHoldingsInc.Member_70949588-c56e-4392-bfb7-e3627644b3b4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoLtdMember_c2d7c489-3081-488c-a7f5-2bad4f7198b7" xlink:href="crto-20251231.xsd#crto_CriteoLtdMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_CriteoLtdMember_c2d7c489-3081-488c-a7f5-2bad4f7198b7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoCorporationMember_a4e28309-8aaa-4f2a-9e1f-428bc991db76" xlink:href="crto-20251231.xsd#crto_CriteoCorporationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_CriteoCorporationMember_a4e28309-8aaa-4f2a-9e1f-428bc991db76" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_DoobeInSiteLtdMember_caef8898-3258-4022-a2b2-09cc27a1070a" xlink:href="crto-20251231.xsd#crto_DoobeInSiteLtdMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_DoobeInSiteLtdMember_caef8898-3258-4022-a2b2-09cc27a1070a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoGmbhMember_a735ae54-e893-4166-aae4-ced0f0349219" xlink:href="crto-20251231.xsd#crto_CriteoGmbhMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_CriteoGmbhMember_a735ae54-e893-4166-aae4-ced0f0349219" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoNordicsABSwedenMember_f770c406-8ab1-4d2e-b9bf-b45343c64898" xlink:href="crto-20251231.xsd#crto_CriteoNordicsABSwedenMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_CriteoNordicsABSwedenMember_f770c406-8ab1-4d2e-b9bf-b45343c64898" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoKoreaLtd.KoreaMember_00ebee12-5116-4499-b546-1e87591778c0" xlink:href="crto-20251231.xsd#crto_CriteoKoreaLtd.KoreaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_CriteoKoreaLtd.KoreaMember_00ebee12-5116-4499-b546-1e87591778c0" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoKKMember_8c47500c-7143-493f-94dc-ccae58c6a8cc" xlink:href="crto-20251231.xsd#crto_CriteoKKMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_CriteoKKMember_8c47500c-7143-493f-94dc-ccae58c6a8cc" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoDoBrasilDesenvolvimeNtoDeServiosDeInternetLTDAMember_4cb50f36-47fd-46d7-8484-3747b24ecb53" xlink:href="crto-20251231.xsd#crto_CriteoDoBrasilDesenvolvimeNtoDeServiosDeInternetLTDAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_CriteoDoBrasilDesenvolvimeNtoDeServiosDeInternetLTDAMember_4cb50f36-47fd-46d7-8484-3747b24ecb53" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoBVMember_df4f9212-055e-4c6a-bd0d-4e361178f5ca" xlink:href="crto-20251231.xsd#crto_CriteoBVMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_CriteoBVMember_df4f9212-055e-4c6a-bd0d-4e361178f5ca" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoAustraliaPtyLtdMember_92c03f8a-1e03-4681-b8b1-9fa4cd3688ce" xlink:href="crto-20251231.xsd#crto_CriteoAustraliaPtyLtdMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_CriteoAustraliaPtyLtdMember_92c03f8a-1e03-4681-b8b1-9fa4cd3688ce" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoSrlMember_973d17e9-e64b-40bd-83c8-febf53ba3050" xlink:href="crto-20251231.xsd#crto_CriteoSrlMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_CriteoSrlMember_973d17e9-e64b-40bd-83c8-febf53ba3050" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoAdvertisingBeijingCo.LtdMember_e6f3f306-7800-410b-93e6-51aa76bc69bc" xlink:href="crto-20251231.xsd#crto_CriteoAdvertisingBeijingCo.LtdMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_CriteoAdvertisingBeijingCo.LtdMember_e6f3f306-7800-410b-93e6-51aa76bc69bc" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_BrandcrushMember_55ad0441-27aa-4025-9ae1-6d0b936b1d3a" xlink:href="crto-20251231.xsd#crto_BrandcrushMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_BrandcrushMember_55ad0441-27aa-4025-9ae1-6d0b936b1d3a" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoSingaporePte.Ltd.Member_63f12970-d7be-42cb-843d-3cea1c208ae0" xlink:href="crto-20251231.xsd#crto_CriteoSingaporePte.Ltd.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_CriteoSingaporePte.Ltd.Member_63f12970-d7be-42cb-843d-3cea1c208ae0" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoLLCMember_060fd938-1c41-45c7-9409-e46801d3b12e" xlink:href="crto-20251231.xsd#crto_CriteoLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_CriteoLLCMember_060fd938-1c41-45c7-9409-e46801d3b12e" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoEuropaMMSLMember_ffa0a9ad-77e2-4e79-8888-fc0d9e06c588" xlink:href="crto-20251231.xsd#crto_CriteoEuropaMMSLMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_CriteoEuropaMMSLMember_ffa0a9ad-77e2-4e79-8888-fc0d9e06c588" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoEspanaS.L.Member_ea5b52a6-2bd1-48f7-a628-eabe0adb7036" xlink:href="crto-20251231.xsd#crto_CriteoEspanaS.L.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_CriteoEspanaS.L.Member_ea5b52a6-2bd1-48f7-a628-eabe0adb7036" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoCanadaCorp.Member_231f35fe-8681-41cf-bb2f-0d3360188215" xlink:href="crto-20251231.xsd#crto_CriteoCanadaCorp.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_CriteoCanadaCorp.Member_231f35fe-8681-41cf-bb2f-0d3360188215" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoReklamclkHizmetleriveTicaretAnonimirketiMember_9f8ef47d-1ba1-4f5f-88a4-fde773e00371" xlink:href="crto-20251231.xsd#crto_CriteoReklamclkHizmetleriveTicaretAnonimirketiMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_CriteoReklamclkHizmetleriveTicaretAnonimirketiMember_9f8ef47d-1ba1-4f5f-88a4-fde773e00371" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoMEAFZLLCMember_3492d791-644c-44e9-b28a-814accd47105" xlink:href="crto-20251231.xsd#crto_CriteoMEAFZLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_CriteoMEAFZLLCMember_3492d791-644c-44e9-b28a-814accd47105" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoIndiaPvtLtdIndiaMember_1c88222a-272c-42f5-b7e9-3c0910b2eeee" xlink:href="crto-20251231.xsd#crto_CriteoIndiaPvtLtdIndiaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_CriteoIndiaPvtLtdIndiaMember_1c88222a-272c-42f5-b7e9-3c0910b2eeee" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_BidswitchGmbHMember_25da43aa-8fa2-4ef0-9b0b-9954c2e684b9" xlink:href="crto-20251231.xsd#crto_BidswitchGmbHMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_BidswitchGmbHMember_25da43aa-8fa2-4ef0-9b0b-9954c2e684b9" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_BidswitchIncMember_add34e17-e28a-4595-a5f2-4623cbf193ad" xlink:href="crto-20251231.xsd#crto_BidswitchIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_BidswitchIncMember_add34e17-e28a-4595-a5f2-4623cbf193ad" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_IponwebGmbHSwitzerlandMember_cbc30065-fbdd-4960-b434-6c50f9ee980c" xlink:href="crto-20251231.xsd#crto_IponwebGmbHSwitzerlandMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_IponwebGmbHSwitzerlandMember_cbc30065-fbdd-4960-b434-6c50f9ee980c" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_IponwebLimitedMember_a939392c-af90-4f7e-b085-bfaa6434efb9" xlink:href="crto-20251231.xsd#crto_IponwebLimitedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_IponwebLimitedMember_a939392c-af90-4f7e-b085-bfaa6434efb9" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_IponwebLabsLimitedMember_de9ff407-6a66-4f34-aa7e-6161888abdd3" xlink:href="crto-20251231.xsd#crto_IponwebLabsLimitedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_IponwebLabsLimitedMember_de9ff407-6a66-4f34-aa7e-6161888abdd3" xlink:type="arc" order="28"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_TheMediaGridIncMember_9fed8908-9180-4f1a-9443-5cebc03921a0" xlink:href="crto-20251231.xsd#crto_TheMediaGridIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_TheMediaGridIncMember_9fed8908-9180-4f1a-9443-5cebc03921a0" xlink:type="arc" order="29"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_IponwebLabsLLCMember_df841eba-df8a-4154-abd4-16b40539f5e7" xlink:href="crto-20251231.xsd#crto_IponwebLabsLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_IponwebLabsLLCMember_df841eba-df8a-4154-abd4-16b40539f5e7" xlink:type="arc" order="30"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoTechnologySRLMember_164c1d4f-fe35-4c98-a68e-10b5b84c80f5" xlink:href="crto-20251231.xsd#crto_CriteoTechnologySRLMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_60a361d5-2cf3-4a99-953e-0c9a473a0a5b" xlink:to="loc_crto_CriteoTechnologySRLMember_164c1d4f-fe35-4c98-a68e-10b5b84c80f5" xlink:type="arc" order="31"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_SaleOfStockPercentOfVotingRightsOwnedAfterTransaction_80981190-e003-480a-a678-c01ca44e78ca" xlink:href="crto-20251231.xsd#crto_SaleOfStockPercentOfVotingRightsOwnedAfterTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_d828ea6e-28bf-46b1-807f-eb1b07184729" xlink:to="loc_crto_SaleOfStockPercentOfVotingRightsOwnedAfterTransaction_80981190-e003-480a-a678-c01ca44e78ca" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction_e6b6e6b1-6bae-44fa-9602-ed393d23d1ee" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_d828ea6e-28bf-46b1-807f-eb1b07184729" xlink:to="loc_us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction_e6b6e6b1-6bae-44fa-9602-ed393d23d1ee" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/PrinciplesandAccountingMethodsNarrativeDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#PrinciplesandAccountingMethodsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/PrinciplesandAccountingMethodsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_dc897d66-1a86-4b68-8cf2-2b5e6f6c21e1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_543b8900-778d-48a5-b489-e1cd0baa329f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_dc897d66-1a86-4b68-8cf2-2b5e6f6c21e1" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_543b8900-778d-48a5-b489-e1cd0baa329f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_14880e94-7251-470e-8a29-af0d435354c1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_543b8900-778d-48a5-b489-e1cd0baa329f" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_14880e94-7251-470e-8a29-af0d435354c1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_14880e94-7251-470e-8a29-af0d435354c1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_14880e94-7251-470e-8a29-af0d435354c1" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_14880e94-7251-470e-8a29-af0d435354c1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_dffc7ede-1317-4da7-8717-3d43531b02fa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_14880e94-7251-470e-8a29-af0d435354c1" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_dffc7ede-1317-4da7-8717-3d43531b02fa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComputerSoftwareIntangibleAssetMember_6f266e12-e6ca-4e58-87ea-7a7750a2dd6d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComputerSoftwareIntangibleAssetMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_dffc7ede-1317-4da7-8717-3d43531b02fa" xlink:to="loc_us-gaap_ComputerSoftwareIntangibleAssetMember_6f266e12-e6ca-4e58-87ea-7a7750a2dd6d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_bf84e4f7-8723-4c53-adab-714da9d89d03" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_543b8900-778d-48a5-b489-e1cd0baa329f" xlink:to="loc_srt_RangeAxis_bf84e4f7-8723-4c53-adab-714da9d89d03" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_bf84e4f7-8723-4c53-adab-714da9d89d03_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_bf84e4f7-8723-4c53-adab-714da9d89d03" xlink:to="loc_srt_RangeMember_bf84e4f7-8723-4c53-adab-714da9d89d03_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_d46d53e8-b98e-4174-b57e-5030596e8392" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_bf84e4f7-8723-4c53-adab-714da9d89d03" xlink:to="loc_srt_RangeMember_d46d53e8-b98e-4174-b57e-5030596e8392" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_644235f4-c585-4552-918c-1a90ae343c32" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_d46d53e8-b98e-4174-b57e-5030596e8392" xlink:to="loc_srt_MinimumMember_644235f4-c585-4552-918c-1a90ae343c32" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_bea93ad6-6a4e-4a46-abb8-729a57adc3c8" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_d46d53e8-b98e-4174-b57e-5030596e8392" xlink:to="loc_srt_MaximumMember_bea93ad6-6a4e-4a46-abb8-729a57adc3c8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_3af87860-ea3b-496c-a368-40ccfc8f894d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_543b8900-778d-48a5-b489-e1cd0baa329f" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_3af87860-ea3b-496c-a368-40ccfc8f894d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_3af87860-ea3b-496c-a368-40ccfc8f894d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_3af87860-ea3b-496c-a368-40ccfc8f894d" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_3af87860-ea3b-496c-a368-40ccfc8f894d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_dfb67ef1-dce1-46a1-96da-e520e4980e2a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_3af87860-ea3b-496c-a368-40ccfc8f894d" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_dfb67ef1-dce1-46a1-96da-e520e4980e2a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_ServersAndNetworkingEquipmentMember_52e1e112-1a6b-473b-87bc-2f1c1b8aa343" xlink:href="crto-20251231.xsd#crto_ServersAndNetworkingEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_dfb67ef1-dce1-46a1-96da-e520e4980e2a" xlink:to="loc_crto_ServersAndNetworkingEquipmentMember_52e1e112-1a6b-473b-87bc-2f1c1b8aa343" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_FurnitureandEquipmentMember_eb87187b-3361-483f-9477-22d38c7bba78" xlink:href="crto-20251231.xsd#crto_FurnitureandEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_dfb67ef1-dce1-46a1-96da-e520e4980e2a" xlink:to="loc_crto_FurnitureandEquipmentMember_eb87187b-3361-483f-9477-22d38c7bba78" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationTypeAxis_d3dbce5f-cd68-488c-b6f5-408777c885fc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReclassificationTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_543b8900-778d-48a5-b489-e1cd0baa329f" xlink:to="loc_us-gaap_ReclassificationTypeAxis_d3dbce5f-cd68-488c-b6f5-408777c885fc" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationTypeDomain_d3dbce5f-cd68-488c-b6f5-408777c885fc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReclassificationTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ReclassificationTypeAxis_d3dbce5f-cd68-488c-b6f5-408777c885fc" xlink:to="loc_us-gaap_ReclassificationTypeDomain_d3dbce5f-cd68-488c-b6f5-408777c885fc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationTypeDomain_eb5390ba-fae1-4fd0-8bbf-06faf937f0df" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReclassificationTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ReclassificationTypeAxis_d3dbce5f-cd68-488c-b6f5-408777c885fc" xlink:to="loc_us-gaap_ReclassificationTypeDomain_eb5390ba-fae1-4fd0-8bbf-06faf937f0df" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationOtherMember_d3d2f611-8e0f-4659-b2f9-bfac04ab0f37" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReclassificationOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationTypeDomain_eb5390ba-fae1-4fd0-8bbf-06faf937f0df" xlink:to="loc_us-gaap_ReclassificationOtherMember_d3d2f611-8e0f-4659-b2f9-bfac04ab0f37" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RestatementAxis_8ec0929c-af2e-4908-b475-b1f1cb42e69a" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RestatementAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_543b8900-778d-48a5-b489-e1cd0baa329f" xlink:to="loc_srt_RestatementAxis_8ec0929c-af2e-4908-b475-b1f1cb42e69a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RestatementDomain_8ec0929c-af2e-4908-b475-b1f1cb42e69a_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RestatementDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RestatementAxis_8ec0929c-af2e-4908-b475-b1f1cb42e69a" xlink:to="loc_srt_RestatementDomain_8ec0929c-af2e-4908-b475-b1f1cb42e69a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RestatementDomain_07576f83-f680-4c3f-bc47-0feb05ce7325" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RestatementDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RestatementAxis_8ec0929c-af2e-4908-b475-b1f1cb42e69a" xlink:to="loc_srt_RestatementDomain_07576f83-f680-4c3f-bc47-0feb05ce7325" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RevisionOfPriorPeriodReclassificationAdjustmentMember_86e40ed4-50a0-48dc-b9af-a65ba41e648b" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RevisionOfPriorPeriodReclassificationAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RestatementDomain_07576f83-f680-4c3f-bc47-0feb05ce7325" xlink:to="loc_srt_RevisionOfPriorPeriodReclassificationAdjustmentMember_86e40ed4-50a0-48dc-b9af-a65ba41e648b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_9fbb8c4d-8d4b-43f1-a3db-9f6f46193e0e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_543b8900-778d-48a5-b489-e1cd0baa329f" xlink:to="loc_us-gaap_AwardTypeAxis_9fbb8c4d-8d4b-43f1-a3db-9f6f46193e0e" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_9fbb8c4d-8d4b-43f1-a3db-9f6f46193e0e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_9fbb8c4d-8d4b-43f1-a3db-9f6f46193e0e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_9fbb8c4d-8d4b-43f1-a3db-9f6f46193e0e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c50a29f1-1c08-4e03-8786-380c5db6bb38" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_9fbb8c4d-8d4b-43f1-a3db-9f6f46193e0e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c50a29f1-1c08-4e03-8786-380c5db6bb38" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_RestrictedStockUnitRSUsAndPerformanceSharesUnitsPSUsMember_365e834d-1f0c-484d-aa2c-f71812ac195d" xlink:href="crto-20251231.xsd#crto_RestrictedStockUnitRSUsAndPerformanceSharesUnitsPSUsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c50a29f1-1c08-4e03-8786-380c5db6bb38" xlink:to="loc_crto_RestrictedStockUnitRSUsAndPerformanceSharesUnitsPSUsMember_365e834d-1f0c-484d-aa2c-f71812ac195d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfOperatingSegments_50a0a086-860d-44d2-b54e-ce15b77276d5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NumberOfOperatingSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_dc897d66-1a86-4b68-8cf2-2b5e6f6c21e1" xlink:to="loc_us-gaap_NumberOfOperatingSegments_50a0a086-860d-44d2-b54e-ce15b77276d5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfReportableSegments_05c6162c-fe05-493e-b837-d38f693d1aa8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NumberOfReportableSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_dc897d66-1a86-4b68-8cf2-2b5e6f6c21e1" xlink:to="loc_us-gaap_NumberOfReportableSegments_05c6162c-fe05-493e-b837-d38f693d1aa8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_a3a5663e-03fb-46a5-9fa6-8cd4aaf1f765" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_dc897d66-1a86-4b68-8cf2-2b5e6f6c21e1" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_a3a5663e-03fb-46a5-9fa6-8cd4aaf1f765" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_ea97d7d7-2c09-4e04-b62e-906aa4595e2c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_dc897d66-1a86-4b68-8cf2-2b5e6f6c21e1" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_ea97d7d7-2c09-4e04-b62e-906aa4595e2c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfReportingUnits_f310327e-2464-42ca-ac90-be62b689fa3e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NumberOfReportingUnits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_dc897d66-1a86-4b68-8cf2-2b5e6f6c21e1" xlink:to="loc_us-gaap_NumberOfReportingUnits_f310327e-2464-42ca-ac90-be62b689fa3e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CIRTaxCreditsOffsetAgainstRDExpenses_b27859bd-a23b-4c7b-be61-958880890013" xlink:href="crto-20251231.xsd#crto_CIRTaxCreditsOffsetAgainstRDExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_dc897d66-1a86-4b68-8cf2-2b5e6f6c21e1" xlink:to="loc_crto_CIRTaxCreditsOffsetAgainstRDExpenses_b27859bd-a23b-4c7b-be61-958880890013" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdvertisingExpense_7e9c7d3b-797f-4b0c-a7a8-ea6a075616aa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdvertisingExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_dc897d66-1a86-4b68-8cf2-2b5e6f6c21e1" xlink:to="loc_us-gaap_AdvertisingExpense_7e9c7d3b-797f-4b0c-a7a8-ea6a075616aa" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_39e0def6-710a-455a-9b36-b5c0f432d6fe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_dc897d66-1a86-4b68-8cf2-2b5e6f6c21e1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_39e0def6-710a-455a-9b36-b5c0f432d6fe" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_PrepaidOtherTaxesandOtherTaxesReceivable_39ad0305-a01f-4718-9f5e-24a53a0f309f" xlink:href="crto-20251231.xsd#crto_PrepaidOtherTaxesandOtherTaxesReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_dc897d66-1a86-4b68-8cf2-2b5e6f6c21e1" xlink:to="loc_crto_PrepaidOtherTaxesandOtherTaxesReceivable_39ad0305-a01f-4718-9f5e-24a53a0f309f" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccrualForTaxesOtherThanIncomeTaxesCurrent_57e859ff-8029-4b76-9a70-07de36653aa7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccrualForTaxesOtherThanIncomeTaxesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_dc897d66-1a86-4b68-8cf2-2b5e6f6c21e1" xlink:to="loc_us-gaap_AccrualForTaxesOtherThanIncomeTaxesCurrent_57e859ff-8029-4b76-9a70-07de36653aa7" xlink:type="arc" order="9"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/RestructuringandOtherExitCostsNarrativeDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#RestructuringandOtherExitCostsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/RestructuringandOtherExitCostsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_1cf4eec4-dd88-43f2-8122-c6e199a06312" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestructuringCostAndReserveLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_966484d8-96ff-40fe-8f16-51d0612a9fd4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_1cf4eec4-dd88-43f2-8122-c6e199a06312" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_966484d8-96ff-40fe-8f16-51d0612a9fd4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_af36174c-0d38-463b-9203-4d34447f33dd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_966484d8-96ff-40fe-8f16-51d0612a9fd4" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_af36174c-0d38-463b-9203-4d34447f33dd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_af36174c-0d38-463b-9203-4d34447f33dd_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_af36174c-0d38-463b-9203-4d34447f33dd" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_af36174c-0d38-463b-9203-4d34447f33dd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_4585f3fd-3471-4fed-afa8-2f8eceddf231" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_af36174c-0d38-463b-9203-4d34447f33dd" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_4585f3fd-3471-4fed-afa8-2f8eceddf231" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_SalesAndOperationsExpensesMember_5660c519-89ef-4552-85f4-6fb701c34412" xlink:href="crto-20251231.xsd#crto_SalesAndOperationsExpensesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_4585f3fd-3471-4fed-afa8-2f8eceddf231" xlink:to="loc_crto_SalesAndOperationsExpensesMember_5660c519-89ef-4552-85f4-6fb701c34412" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpenseMember_982884a5-dc31-45cf-b236-a30ebd3a8727" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResearchAndDevelopmentExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_4585f3fd-3471-4fed-afa8-2f8eceddf231" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpenseMember_982884a5-dc31-45cf-b236-a30ebd3a8727" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpenseMember_5db4b24c-0e4f-4aba-8510-34331347360b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeneralAndAdministrativeExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_4585f3fd-3471-4fed-afa8-2f8eceddf231" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpenseMember_5db4b24c-0e4f-4aba-8510-34331347360b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringCharges_55afd93d-d0bd-4c71-aab1-2ec3c123ad83" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestructuringCharges"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_1cf4eec4-dd88-43f2-8122-c6e199a06312" xlink:to="loc_us-gaap_RestructuringCharges_55afd93d-d0bd-4c71-aab1-2ec3c123ad83" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringIncurredCostStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration_21ff9efb-e2ed-4910-ba51-66293b4c337d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestructuringIncurredCostStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_1cf4eec4-dd88-43f2-8122-c6e199a06312" xlink:to="loc_us-gaap_RestructuringIncurredCostStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration_21ff9efb-e2ed-4910-ba51-66293b4c337d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringAndRelatedCostNumberOfPositionsEliminated_3529d257-219c-465f-aef6-691de1995393" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestructuringAndRelatedCostNumberOfPositionsEliminated"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_1cf4eec4-dd88-43f2-8122-c6e199a06312" xlink:to="loc_us-gaap_RestructuringAndRelatedCostNumberOfPositionsEliminated_3529d257-219c-465f-aef6-691de1995393" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/SegmentinformationScheduleofSegmentReportingInformationDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#SegmentinformationScheduleofSegmentReportingInformationDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/SegmentinformationScheduleofSegmentReportingInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_2adec431-9245-4f4a-b563-3e9d846319e8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_04b698e3-1250-4b8a-a91a-0dde0b7bfd3e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_2adec431-9245-4f4a-b563-3e9d846319e8" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_04b698e3-1250-4b8a-a91a-0dde0b7bfd3e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_b653c7f7-4cce-4297-8a15-cf4fee8fc4fc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_04b698e3-1250-4b8a-a91a-0dde0b7bfd3e" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_b653c7f7-4cce-4297-8a15-cf4fee8fc4fc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_b653c7f7-4cce-4297-8a15-cf4fee8fc4fc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_b653c7f7-4cce-4297-8a15-cf4fee8fc4fc" xlink:to="loc_us-gaap_SegmentDomain_b653c7f7-4cce-4297-8a15-cf4fee8fc4fc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_b05f13c6-e951-4fd2-882c-1c88c7511ef8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_b653c7f7-4cce-4297-8a15-cf4fee8fc4fc" xlink:to="loc_us-gaap_SegmentDomain_b05f13c6-e951-4fd2-882c-1c88c7511ef8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_RetailMediaMember_e0efe197-1cae-4134-8fd5-d122902c5601" xlink:href="crto-20251231.xsd#crto_RetailMediaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_b05f13c6-e951-4fd2-882c-1c88c7511ef8" xlink:to="loc_crto_RetailMediaMember_e0efe197-1cae-4134-8fd5-d122902c5601" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_PerformanceMediaMember_255ed4ad-3cfe-4b5e-92bb-c85d118bfd70" xlink:href="crto-20251231.xsd#crto_PerformanceMediaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_b05f13c6-e951-4fd2-882c-1c88c7511ef8" xlink:to="loc_crto_PerformanceMediaMember_255ed4ad-3cfe-4b5e-92bb-c85d118bfd70" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_8059b99f-253b-4057-98fb-7700ce60c520" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_2adec431-9245-4f4a-b563-3e9d846319e8" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_8059b99f-253b-4057-98fb-7700ce60c520" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_113158ed-15f1-4305-b888-0f73c5398c81" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostOfGoodsAndServicesSold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_2adec431-9245-4f4a-b563-3e9d846319e8" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_113158ed-15f1-4305-b888-0f73c5398c81" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_GrossProfitAndOtherCostsOfRevenue_a0e8be48-a273-4cbb-b86d-0598f2b83090" xlink:href="crto-20251231.xsd#crto_GrossProfitAndOtherCostsOfRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_2adec431-9245-4f4a-b563-3e9d846319e8" xlink:to="loc_crto_GrossProfitAndOtherCostsOfRevenue_a0e8be48-a273-4cbb-b86d-0598f2b83090" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCostOfOperatingRevenue_23a2ca75-dfc5-47ca-bca6-b680aad91b75" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherCostOfOperatingRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_2adec431-9245-4f4a-b563-3e9d846319e8" xlink:to="loc_us-gaap_OtherCostOfOperatingRevenue_23a2ca75-dfc5-47ca-bca6-b680aad91b75" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_3488e938-f30a-44af-b0dc-0101880e8d53" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GrossProfit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_2adec431-9245-4f4a-b563-3e9d846319e8" xlink:to="loc_us-gaap_GrossProfit_3488e938-f30a-44af-b0dc-0101880e8d53" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpensesAbstract_3c83bdcd-658f-4f9f-bd78-7fa78ca8ba95" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingExpensesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_2adec431-9245-4f4a-b563-3e9d846319e8" xlink:to="loc_us-gaap_OperatingExpensesAbstract_3c83bdcd-658f-4f9f-bd78-7fa78ca8ba95" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_6dd5f730-b9bf-4bd7-83e1-c38d7ee278fe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResearchAndDevelopmentExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_3c83bdcd-658f-4f9f-bd78-7fa78ca8ba95" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_6dd5f730-b9bf-4bd7-83e1-c38d7ee278fe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingAndMarketingExpense_5699201a-c3b5-488d-8f7e-aa4c55b4f1b2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SellingAndMarketingExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_3c83bdcd-658f-4f9f-bd78-7fa78ca8ba95" xlink:to="loc_us-gaap_SellingAndMarketingExpense_5699201a-c3b5-488d-8f7e-aa4c55b4f1b2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpense_e5fbf3fb-c01e-4c7b-a3d6-353971d57a7d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_3c83bdcd-658f-4f9f-bd78-7fa78ca8ba95" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpense_e5fbf3fb-c01e-4c7b-a3d6-353971d57a7d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_06d8e3d5-da2d-4dbf-ad05-6d8c1d684a58" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_3c83bdcd-658f-4f9f-bd78-7fa78ca8ba95" xlink:to="loc_us-gaap_OperatingExpenses_06d8e3d5-da2d-4dbf-ad05-6d8c1d684a58" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_ef29b149-ed9c-49bc-9f30-bffebc2b842c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_2adec431-9245-4f4a-b563-3e9d846319e8" xlink:to="loc_us-gaap_OperatingIncomeLoss_ef29b149-ed9c-49bc-9f30-bffebc2b842c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_b5b529d8-290b-4a7e-a6e8-ef8f609a31dd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_2adec431-9245-4f4a-b563-3e9d846319e8" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_b5b529d8-290b-4a7e-a6e8-ef8f609a31dd" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_ec2ba83e-aa9f-4f92-bd9d-8f6cbb2128b6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_2adec431-9245-4f4a-b563-3e9d846319e8" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_ec2ba83e-aa9f-4f92-bd9d-8f6cbb2128b6" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/FinancialinstrumentsFairValueAssetsMeasuredonaRecurringBasisDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#FinancialinstrumentsFairValueAssetsMeasuredonaRecurringBasisDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/FinancialinstrumentsFairValueAssetsMeasuredonaRecurringBasisDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_4c33d66d-637a-48f5-976d-3db34d4d4cbd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_deab11a2-3eef-4571-b607-93a8267682fc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_4c33d66d-637a-48f5-976d-3db34d4d4cbd" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_deab11a2-3eef-4571-b607-93a8267682fc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_1d819671-af5e-4bbc-b25d-d3879d5d3c6f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_deab11a2-3eef-4571-b607-93a8267682fc" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_1d819671-af5e-4bbc-b25d-d3879d5d3c6f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_1d819671-af5e-4bbc-b25d-d3879d5d3c6f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_1d819671-af5e-4bbc-b25d-d3879d5d3c6f" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_1d819671-af5e-4bbc-b25d-d3879d5d3c6f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_bbfa0144-f1ad-4550-8bcf-9a0bf67335c5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_1d819671-af5e-4bbc-b25d-d3879d5d3c6f" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_bbfa0144-f1ad-4550-8bcf-9a0bf67335c5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_6c871280-71b6-4f61-9ab5-c97c5e000a52" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_bbfa0144-f1ad-4550-8bcf-9a0bf67335c5" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_6c871280-71b6-4f61-9ab5-c97c5e000a52" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_f454992c-908d-44df-a78f-afa284faa769" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_bbfa0144-f1ad-4550-8bcf-9a0bf67335c5" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_f454992c-908d-44df-a78f-afa284faa769" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsAxis_23a00dea-14b0-4f8b-97e8-028d9e18fd57" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_deab11a2-3eef-4571-b607-93a8267682fc" xlink:to="loc_us-gaap_CashAndCashEquivalentsAxis_23a00dea-14b0-4f8b-97e8-028d9e18fd57" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_23a00dea-14b0-4f8b-97e8-028d9e18fd57_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CashAndCashEquivalentsAxis_23a00dea-14b0-4f8b-97e8-028d9e18fd57" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_23a00dea-14b0-4f8b-97e8-028d9e18fd57_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_6d61d974-4ed6-4f13-b88d-1a80eb3ec10f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CashAndCashEquivalentsAxis_23a00dea-14b0-4f8b-97e8-028d9e18fd57" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_6d61d974-4ed6-4f13-b88d-1a80eb3ec10f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashMember_f36f9202-dae3-4b70-b1c6-120be7cbecbf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_6d61d974-4ed6-4f13-b88d-1a80eb3ec10f" xlink:to="loc_us-gaap_CashMember_f36f9202-dae3-4b70-b1c6-120be7cbecbf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MoneyMarketFundsMember_a6fd8dcb-12cc-4fff-9100-77216a4952b8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MoneyMarketFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_6d61d974-4ed6-4f13-b88d-1a80eb3ec10f" xlink:to="loc_us-gaap_MoneyMarketFundsMember_a6fd8dcb-12cc-4fff-9100-77216a4952b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPaperMember_019c27b3-41bc-70de-b34c-51b842e80293" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommercialPaperMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_6d61d974-4ed6-4f13-b88d-1a80eb3ec10f" xlink:to="loc_us-gaap_CommercialPaperMember_019c27b3-41bc-70de-b34c-51b842e80293" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BankTimeDepositsMember_78893e61-b750-4526-bc25-3745513438d6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BankTimeDepositsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_6d61d974-4ed6-4f13-b88d-1a80eb3ec10f" xlink:to="loc_us-gaap_BankTimeDepositsMember_78893e61-b750-4526-bc25-3745513438d6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesMember_019c27b4-5e86-72fc-b726-e2b07c08aa87" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_6d61d974-4ed6-4f13-b88d-1a80eb3ec10f" xlink:to="loc_us-gaap_DebtSecuritiesMember_019c27b4-5e86-72fc-b726-e2b07c08aa87" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019c74eb-f639-74ec-ac0a-923c5c17d9e3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_4c33d66d-637a-48f5-976d-3db34d4d4cbd" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019c74eb-f639-74ec-ac0a-923c5c17d9e3" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/FinancialinstrumentsScheduleofFinancialAssetsDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#FinancialinstrumentsScheduleofFinancialAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/FinancialinstrumentsScheduleofFinancialAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_54fef28a-2a86-4c77-87cb-c198ab24c3ae" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_2809b8b7-3328-40f8-ac58-c20b73e1ea13" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesAvailableForSaleTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_54fef28a-2a86-4c77-87cb-c198ab24c3ae" xlink:to="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_2809b8b7-3328-40f8-ac58-c20b73e1ea13" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_019c27b9-5d7e-7c2a-91bc-bf0f7848a259" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtSecuritiesAvailableForSaleTable_2809b8b7-3328-40f8-ac58-c20b73e1ea13" xlink:to="loc_us-gaap_FinancialInstrumentAxis_019c27b9-5d7e-7c2a-91bc-bf0f7848a259" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019c27b9-5d7e-7c2a-91bc-bf0f7848a259_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019c27b9-5d7e-7c2a-91bc-bf0f7848a259" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019c27b9-5d7e-7c2a-91bc-bf0f7848a259_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019c27b9-5d7e-75fb-9ae3-a9e0bd00a487" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019c27b9-5d7e-7c2a-91bc-bf0f7848a259" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019c27b9-5d7e-75fb-9ae3-a9e0bd00a487" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPaperMember_019c27b6-9622-704a-abc0-364c3e6f040d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommercialPaperMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019c27b9-5d7e-75fb-9ae3-a9e0bd00a487" xlink:to="loc_us-gaap_CommercialPaperMember_019c27b6-9622-704a-abc0-364c3e6f040d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_StructuredDebtSecuritiesMember_019c27ba-54f5-7c9c-87dc-db5095a9969e" xlink:href="crto-20251231.xsd#crto_StructuredDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019c27b9-5d7e-75fb-9ae3-a9e0bd00a487" xlink:to="loc_crto_StructuredDebtSecuritiesMember_019c27ba-54f5-7c9c-87dc-db5095a9969e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateDebtSecuritiesMember_019c27b8-83b5-7cf1-af83-653d0ef26f43" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CorporateDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019c27b9-5d7e-75fb-9ae3-a9e0bd00a487" xlink:to="loc_us-gaap_CorporateDebtSecuritiesMember_019c27b8-83b5-7cf1-af83-653d0ef26f43" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HeldToMaturitySecuritiesFairValue_6c2d9ba2-34e0-4da2-87f1-5bc8152baad3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HeldToMaturitySecuritiesFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_54fef28a-2a86-4c77-87cb-c198ab24c3ae" xlink:to="loc_us-gaap_HeldToMaturitySecuritiesFairValue_6c2d9ba2-34e0-4da2-87f1-5bc8152baad3" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/TradeReceivablesNarrativeDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#TradeReceivablesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/TradeReceivablesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019c243c-1219-7a9d-83ce-7f70f737d003" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019c243b-c1a6-71f8-801f-6a14ac4d281d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019c243c-1219-7a9d-83ce-7f70f737d003" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019c243b-c1a6-71f8-801f-6a14ac4d281d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019c243c-1219-7f7d-9280-5c071e1ba46c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019c243b-c1a6-71f8-801f-6a14ac4d281d" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019c243c-1219-7f7d-9280-5c071e1ba46c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019c243c-1219-7f7d-9280-5c071e1ba46c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019c243c-1219-7f7d-9280-5c071e1ba46c" xlink:to="loc_us-gaap_SegmentDomain_019c243c-1219-7f7d-9280-5c071e1ba46c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019c243c-1219-73e9-bfe5-557d71a687af" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019c243c-1219-7f7d-9280-5c071e1ba46c" xlink:to="loc_us-gaap_SegmentDomain_019c243c-1219-73e9-bfe5-557d71a687af" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_PerformanceMediaMember_019c243c-3e11-7ec1-9c2b-3fb92f3913ea" xlink:href="crto-20251231.xsd#crto_PerformanceMediaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019c243c-1219-73e9-bfe5-557d71a687af" xlink:to="loc_crto_PerformanceMediaMember_019c243c-3e11-7ec1-9c2b-3fb92f3913ea" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsAccountsReceivablePreviouslyWrittenOffRecovery_abdae378-310c-43e7-9ec1-d4810e6f6c6e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProceedsAccountsReceivablePreviouslyWrittenOffRecovery"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019c243c-1219-7a9d-83ce-7f70f737d003" xlink:to="loc_us-gaap_ProceedsAccountsReceivablePreviouslyWrittenOffRecovery_abdae378-310c-43e7-9ec1-d4810e6f6c6e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_019c243c-1219-7e2c-a7aa-6de6b4bd0fd1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019c243c-1219-7a9d-83ce-7f70f737d003" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_019c243c-1219-7e2c-a7aa-6de6b4bd0fd1" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/OtherCurrentandNoncurrentAssetsNarrativeDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#OtherCurrentandNoncurrentAssetsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/OtherCurrentandNoncurrentAssetsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_crto_OtherNonCurentAssetsLineItems_1c867f3a-521c-4416-96e5-e73ec8c3fb7b" xlink:href="crto-20251231.xsd#crto_OtherNonCurentAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_OtherNonCurentAssetsTable_130a8de5-7f3d-4249-992c-6d47fc015c81" xlink:href="crto-20251231.xsd#crto_OtherNonCurentAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_crto_OtherNonCurentAssetsLineItems_1c867f3a-521c-4416-96e5-e73ec8c3fb7b" xlink:to="loc_crto_OtherNonCurentAssetsTable_130a8de5-7f3d-4249-992c-6d47fc015c81" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_54ea926e-47c3-47b1-82ca-92a9a6abbdba" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_crto_OtherNonCurentAssetsTable_130a8de5-7f3d-4249-992c-6d47fc015c81" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_54ea926e-47c3-47b1-82ca-92a9a6abbdba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_54ea926e-47c3-47b1-82ca-92a9a6abbdba_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_54ea926e-47c3-47b1-82ca-92a9a6abbdba" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_54ea926e-47c3-47b1-82ca-92a9a6abbdba_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_569561df-d718-4511-9d3d-287b5892cb16" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_54ea926e-47c3-47b1-82ca-92a9a6abbdba" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_569561df-d718-4511-9d3d-287b5892cb16" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_IponwebMember_c9992ccf-1ab8-4a46-978b-43f6427b5bb1" xlink:href="crto-20251231.xsd#crto_IponwebMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_569561df-d718-4511-9d3d-287b5892cb16" xlink:to="loc_crto_IponwebMember_c9992ccf-1ab8-4a46-978b-43f6427b5bb1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseAxis_77d37d6a-9342-4e61-aa7a-56eca4e5613e" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_LitigationCaseAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_crto_OtherNonCurentAssetsTable_130a8de5-7f3d-4249-992c-6d47fc015c81" xlink:to="loc_srt_LitigationCaseAxis_77d37d6a-9342-4e61-aa7a-56eca4e5613e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseTypeDomain_77d37d6a-9342-4e61-aa7a-56eca4e5613e_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_LitigationCaseTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_LitigationCaseAxis_77d37d6a-9342-4e61-aa7a-56eca4e5613e" xlink:to="loc_srt_LitigationCaseTypeDomain_77d37d6a-9342-4e61-aa7a-56eca4e5613e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseTypeDomain_9c06ede5-efed-4eae-9c98-18123054b83a" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_LitigationCaseTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_LitigationCaseAxis_77d37d6a-9342-4e61-aa7a-56eca4e5613e" xlink:to="loc_srt_LitigationCaseTypeDomain_9c06ede5-efed-4eae-9c98-18123054b83a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_DoeVs.GoodRxHoldingsInc.Member_8097a7c7-8e82-480a-8079-8ea0a342ecd3" xlink:href="crto-20251231.xsd#crto_DoeVs.GoodRxHoldingsInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_9c06ede5-efed-4eae-9c98-18123054b83a" xlink:to="loc_crto_DoeVs.GoodRxHoldingsInc.Member_8097a7c7-8e82-480a-8079-8ea0a342ecd3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedComputerSoftwareGross_019c74fe-3333-7439-a2c0-d7242941dc3a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CapitalizedComputerSoftwareGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_crto_OtherNonCurentAssetsLineItems_1c867f3a-521c-4416-96e5-e73ec8c3fb7b" xlink:to="loc_us-gaap_CapitalizedComputerSoftwareGross_019c74fe-3333-7439-a2c0-d7242941dc3a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalizedComputerSoftwareAmortization1_019c74ff-9b24-7c80-9798-d359decf2193" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CapitalizedComputerSoftwareAmortization1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_crto_OtherNonCurentAssetsLineItems_1c867f3a-521c-4416-96e5-e73ec8c3fb7b" xlink:to="loc_us-gaap_CapitalizedComputerSoftwareAmortization1_019c74ff-9b24-7c80-9798-d359decf2193" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyReceivable_4e0d84b7-4967-49d7-b52d-419ad8f298bb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossContingencyReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_crto_OtherNonCurentAssetsLineItems_1c867f3a-521c-4416-96e5-e73ec8c3fb7b" xlink:to="loc_us-gaap_LossContingencyReceivable_4e0d84b7-4967-49d7-b52d-419ad8f298bb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCash_019b9405-7b64-77ed-b508-23350370cb43" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_crto_OtherNonCurentAssetsLineItems_1c867f3a-521c-4416-96e5-e73ec8c3fb7b" xlink:to="loc_us-gaap_RestrictedCash_019b9405-7b64-77ed-b508-23350370cb43" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_b3182b9b-8795-4724-89ab-777bf9290ee7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_crto_OtherNonCurentAssetsLineItems_1c867f3a-521c-4416-96e5-e73ec8c3fb7b" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_b3182b9b-8795-4724-89ab-777bf9290ee7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationIndemnificationAssetsAmountAsOfAcquisitionDate_1ac90002-ff44-4ae8-b917-d32f5cd727d1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationIndemnificationAssetsAmountAsOfAcquisitionDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_crto_OtherNonCurentAssetsLineItems_1c867f3a-521c-4416-96e5-e73ec8c3fb7b" xlink:to="loc_us-gaap_BusinessCombinationIndemnificationAssetsAmountAsOfAcquisitionDate_1ac90002-ff44-4ae8-b917-d32f5cd727d1" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/PropertyandEquipmentNetScheduleofNetBookValueDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#PropertyandEquipmentNetScheduleofNetBookValueDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/PropertyandEquipmentNetScheduleofNetBookValueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_e4d1548b-4e3b-4004-b032-f3059b8d9151" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_d39d0d2e-6e93-43b8-88b9-77867dc2ae82" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_e4d1548b-4e3b-4004-b032-f3059b8d9151" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_d39d0d2e-6e93-43b8-88b9-77867dc2ae82" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_59e85569-7887-4295-ae5a-dc882d3caffe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_d39d0d2e-6e93-43b8-88b9-77867dc2ae82" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_59e85569-7887-4295-ae5a-dc882d3caffe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_59e85569-7887-4295-ae5a-dc882d3caffe_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_59e85569-7887-4295-ae5a-dc882d3caffe" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_59e85569-7887-4295-ae5a-dc882d3caffe_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_e5b10f64-c7cf-4787-828c-73648eeb53d9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_59e85569-7887-4295-ae5a-dc882d3caffe" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_e5b10f64-c7cf-4787-828c-73648eeb53d9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComputerEquipmentMember_f19bfd1f-bfbd-4964-a80b-65fe9b281341" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComputerEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_e5b10f64-c7cf-4787-828c-73648eeb53d9" xlink:to="loc_us-gaap_ComputerEquipmentMember_f19bfd1f-bfbd-4964-a80b-65fe9b281341" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FurnitureAndFixturesMember_ec627253-b619-4768-af65-8a4c46223ab4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FurnitureAndFixturesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_e5b10f64-c7cf-4787-828c-73648eeb53d9" xlink:to="loc_us-gaap_FurnitureAndFixturesMember_ec627253-b619-4768-af65-8a4c46223ab4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConstructionInProgressMember_184880e5-124d-4211-9dee-8ed5291124b7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ConstructionInProgressMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_e5b10f64-c7cf-4787-828c-73648eeb53d9" xlink:to="loc_us-gaap_ConstructionInProgressMember_184880e5-124d-4211-9dee-8ed5291124b7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseholdImprovementsMember_08fe8730-c863-4ca7-8e26-6ff2d3739853" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseholdImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_e5b10f64-c7cf-4787-828c-73648eeb53d9" xlink:to="loc_us-gaap_LeaseholdImprovementsMember_08fe8730-c863-4ca7-8e26-6ff2d3739853" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_9051aad3-d742-4387-8b9a-30689b73770e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_e4d1548b-4e3b-4004-b032-f3059b8d9151" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_9051aad3-d742-4387-8b9a-30689b73770e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_3f2fef3f-8705-48ad-a349-b4b57fab35c9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_e4d1548b-4e3b-4004-b032-f3059b8d9151" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_3f2fef3f-8705-48ad-a349-b4b57fab35c9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_920d87da-3a76-4383-ae6a-94a619ad1352" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_e4d1548b-4e3b-4004-b032-f3059b8d9151" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_920d87da-3a76-4383-ae6a-94a619ad1352" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/IntangibleassetsScheduleofFiniteLivedIntangibleAssetsDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#IntangibleassetsScheduleofFiniteLivedIntangibleAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/IntangibleassetsScheduleofFiniteLivedIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_a21d6205-e0f0-4350-9854-30dfd71f6a61" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsTable_81f11788-8d5b-4bbd-b705-6dbb4f1a7bcf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_a21d6205-e0f0-4350-9854-30dfd71f6a61" xlink:to="loc_us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsTable_81f11788-8d5b-4bbd-b705-6dbb4f1a7bcf" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_64ec1a4c-d2af-425d-b35d-7d84b63d435b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsTable_81f11788-8d5b-4bbd-b705-6dbb4f1a7bcf" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_64ec1a4c-d2af-425d-b35d-7d84b63d435b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_64ec1a4c-d2af-425d-b35d-7d84b63d435b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_64ec1a4c-d2af-425d-b35d-7d84b63d435b" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_64ec1a4c-d2af-425d-b35d-7d84b63d435b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_b3b66708-86c6-413f-89e4-e1927cb872d5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_64ec1a4c-d2af-425d-b35d-7d84b63d435b" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_b3b66708-86c6-413f-89e4-e1927cb872d5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComputerSoftwareIntangibleAssetMember_f74589dc-50d0-40f8-b6ff-43f71633c9a9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComputerSoftwareIntangibleAssetMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_b3b66708-86c6-413f-89e4-e1927cb872d5" xlink:to="loc_us-gaap_ComputerSoftwareIntangibleAssetMember_f74589dc-50d0-40f8-b6ff-43f71633c9a9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_TechnologyMember_3baaf95b-165f-4739-97f1-6aa49ea79297" xlink:href="crto-20251231.xsd#crto_TechnologyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_b3b66708-86c6-413f-89e4-e1927cb872d5" xlink:to="loc_crto_TechnologyMember_3baaf95b-165f-4739-97f1-6aa49ea79297" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_6269e111-9043-44a1-8c3a-90769ca118b4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_b3b66708-86c6-413f-89e4-e1927cb872d5" xlink:to="loc_us-gaap_CustomerRelationshipsMember_6269e111-9043-44a1-8c3a-90769ca118b4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_a9093215-53ce-4c8a-8fbf-096ce242d50d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsTable_81f11788-8d5b-4bbd-b705-6dbb4f1a7bcf" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_a9093215-53ce-4c8a-8fbf-096ce242d50d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_a9093215-53ce-4c8a-8fbf-096ce242d50d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_a9093215-53ce-4c8a-8fbf-096ce242d50d" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_a9093215-53ce-4c8a-8fbf-096ce242d50d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_25d6209c-3669-422c-bd49-f71af6960de1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_a9093215-53ce-4c8a-8fbf-096ce242d50d" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_25d6209c-3669-422c-bd49-f71af6960de1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComputerSoftwareIntangibleAssetMember_d6c6e1de-4ff0-459b-a7f8-91ee4a572b6d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComputerSoftwareIntangibleAssetMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_25d6209c-3669-422c-bd49-f71af6960de1" xlink:to="loc_us-gaap_ComputerSoftwareIntangibleAssetMember_d6c6e1de-4ff0-459b-a7f8-91ee4a572b6d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_28b45b3d-2e4c-49ce-949a-4af535fbf7fc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IntangibleAssetsGrossExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_a21d6205-e0f0-4350-9854-30dfd71f6a61" xlink:to="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_28b45b3d-2e4c-49ce-949a-4af535fbf7fc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_1ca5027c-ea55-43b8-9e9a-1327000f00fe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_a21d6205-e0f0-4350-9854-30dfd71f6a61" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_1ca5027c-ea55-43b8-9e9a-1327000f00fe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_IntangibleAssetsAccumulatedImpairmentExcludingGoodwill_70327103-3127-490e-97ab-3a48b82a3be3" xlink:href="crto-20251231.xsd#crto_IntangibleAssetsAccumulatedImpairmentExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_a21d6205-e0f0-4350-9854-30dfd71f6a61" xlink:to="loc_crto_IntangibleAssetsAccumulatedImpairmentExcludingGoodwill_70327103-3127-490e-97ab-3a48b82a3be3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_f065ed9e-c18b-4356-85e2-f6c1ad20b1db" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_a21d6205-e0f0-4350-9854-30dfd71f6a61" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_f065ed9e-c18b-4356-85e2-f6c1ad20b1db" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/IntangibleassetsNarrativeDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#IntangibleassetsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/IntangibleassetsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_019c2e92-7b8d-70aa-89ac-e0c7c0db4607" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsTable_019c2e92-1f0d-7c27-aa45-81b33ed962c3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_019c2e92-7b8d-70aa-89ac-e0c7c0db4607" xlink:to="loc_us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsTable_019c2e92-1f0d-7c27-aa45-81b33ed962c3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019c2e92-bebb-70b0-a732-7dc7247c4ca9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfIndefiniteLivedIntangibleAssetsTable_019c2e92-1f0d-7c27-aa45-81b33ed962c3" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019c2e92-bebb-70b0-a732-7dc7247c4ca9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019c2e92-bebb-70b0-a732-7dc7247c4ca9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019c2e92-bebb-70b0-a732-7dc7247c4ca9" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019c2e92-bebb-70b0-a732-7dc7247c4ca9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019c2e92-bebb-7539-9d54-75a8b5972187" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_019c2e92-bebb-70b0-a732-7dc7247c4ca9" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019c2e92-bebb-7539-9d54-75a8b5972187" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComputerSoftwareIntangibleAssetMember_019c2e92-bebb-74a6-b0f0-9b883fa4e2bd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComputerSoftwareIntangibleAssetMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_019c2e92-bebb-7539-9d54-75a8b5972187" xlink:to="loc_us-gaap_ComputerSoftwareIntangibleAssetMember_019c2e92-bebb-74a6-b0f0-9b883fa4e2bd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill_019c2462-5fff-7c63-851e-4680ab41731e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_019c2e92-7b8d-70aa-89ac-e0c7c0db4607" xlink:to="loc_us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill_019c2462-5fff-7c63-851e-4680ab41731e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentIntangibleAssetStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration_019c75b5-2bba-7b30-973f-0893da130e3b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ImpairmentIntangibleAssetStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_019c2e92-7b8d-70aa-89ac-e0c7c0db4607" xlink:to="loc_us-gaap_ImpairmentIntangibleAssetStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration_019c75b5-2bba-7b30-973f-0893da130e3b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_019c2e92-bebb-7c0b-8e28-d2d043cce5a7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_019c2e92-7b8d-70aa-89ac-e0c7c0db4607" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_019c2e92-bebb-7c0b-8e28-d2d043cce5a7" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/IntangibleassetsScheduleofExpectedAmortizationExpenseforIntangibleassetsDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#IntangibleassetsScheduleofExpectedAmortizationExpenseforIntangibleassetsDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/IntangibleassetsScheduleofExpectedAmortizationExpenseforIntangibleassetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_972731c1-7d17-459b-b04f-d50fda63f0f5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_b1dd0880-772f-4175-a5a5-3bc20b6f45e4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_972731c1-7d17-459b-b04f-d50fda63f0f5" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_b1dd0880-772f-4175-a5a5-3bc20b6f45e4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_9a88b623-d706-4d03-9cef-41915df74455" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_b1dd0880-772f-4175-a5a5-3bc20b6f45e4" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_9a88b623-d706-4d03-9cef-41915df74455" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_9a88b623-d706-4d03-9cef-41915df74455_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_9a88b623-d706-4d03-9cef-41915df74455" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_9a88b623-d706-4d03-9cef-41915df74455_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_f995ad2a-3800-499d-91ca-111a4aa57652" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_9a88b623-d706-4d03-9cef-41915df74455" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_f995ad2a-3800-499d-91ca-111a4aa57652" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComputerSoftwareIntangibleAssetMember_5d288352-0b97-49f7-82f7-1bca8fafa6af" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComputerSoftwareIntangibleAssetMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_f995ad2a-3800-499d-91ca-111a4aa57652" xlink:to="loc_us-gaap_ComputerSoftwareIntangibleAssetMember_5d288352-0b97-49f7-82f7-1bca8fafa6af" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_TechnologyAndCustomerRelationshipsMember_e0c10751-353b-44da-8c90-e1d52d6311ee" xlink:href="crto-20251231.xsd#crto_TechnologyAndCustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_f995ad2a-3800-499d-91ca-111a4aa57652" xlink:to="loc_crto_TechnologyAndCustomerRelationshipsMember_e0c10751-353b-44da-8c90-e1d52d6311ee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_32127106-b145-4d63-8b76-495408744efd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_972731c1-7d17-459b-b04f-d50fda63f0f5" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths_32127106-b145-4d63-8b76-495408744efd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_b14ca4c3-de6b-4408-b0fe-499ff3d73ad8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_972731c1-7d17-459b-b04f-d50fda63f0f5" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo_b14ca4c3-de6b-4408-b0fe-499ff3d73ad8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_b102970a-0fc1-4190-a291-4789c6c9cd5c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_972731c1-7d17-459b-b04f-d50fda63f0f5" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree_b102970a-0fc1-4190-a291-4789c6c9cd5c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_46d80a7f-607c-412b-b7cf-6cb46073cf50" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_972731c1-7d17-459b-b04f-d50fda63f0f5" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFour_46d80a7f-607c-412b-b7cf-6cb46073cf50" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive_7aaad589-71b9-453e-80ce-8fea642d7ee1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_972731c1-7d17-459b-b04f-d50fda63f0f5" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearFive_7aaad589-71b9-453e-80ce-8fea642d7ee1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive_303a17f9-322b-41e5-bde6-673d573514e3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_972731c1-7d17-459b-b04f-d50fda63f0f5" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive_303a17f9-322b-41e5-bde6-673d573514e3" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_9ea0c7b1-a843-4da9-99b4-dcf1c7d0bbc6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_972731c1-7d17-459b-b04f-d50fda63f0f5" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_9ea0c7b1-a843-4da9-99b4-dcf1c7d0bbc6" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/GoodwillDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#GoodwillDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/GoodwillDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems_ea9dc59d-948f-4765-8a80-dc97edb402bb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_80b21d3c-9259-4a76-93f0-a4a43321d56c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfGoodwillTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_ea9dc59d-948f-4765-8a80-dc97edb402bb" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_80b21d3c-9259-4a76-93f0-a4a43321d56c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_57f0a26c-c5d2-4869-ae33-dd9f1b7d82ca" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_80b21d3c-9259-4a76-93f0-a4a43321d56c" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_57f0a26c-c5d2-4869-ae33-dd9f1b7d82ca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_57f0a26c-c5d2-4869-ae33-dd9f1b7d82ca_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_57f0a26c-c5d2-4869-ae33-dd9f1b7d82ca" xlink:to="loc_us-gaap_SegmentDomain_57f0a26c-c5d2-4869-ae33-dd9f1b7d82ca_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_d3efafb0-beaf-4263-bee8-5e9ea8917189" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_57f0a26c-c5d2-4869-ae33-dd9f1b7d82ca" xlink:to="loc_us-gaap_SegmentDomain_d3efafb0-beaf-4263-bee8-5e9ea8917189" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_RetailMediaMember_68e9d9d1-6e28-40c7-bae9-ee28282effe7" xlink:href="crto-20251231.xsd#crto_RetailMediaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_d3efafb0-beaf-4263-bee8-5e9ea8917189" xlink:to="loc_crto_RetailMediaMember_68e9d9d1-6e28-40c7-bae9-ee28282effe7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_PerformanceMediaMember_0423171c-849d-4ffd-8eca-f09b1c646052" xlink:href="crto-20251231.xsd#crto_PerformanceMediaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_d3efafb0-beaf-4263-bee8-5e9ea8917189" xlink:to="loc_crto_PerformanceMediaMember_0423171c-849d-4ffd-8eca-f09b1c646052" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfReportableSegments_e5679146-6650-4c86-ac29-f25fdc934313" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NumberOfReportableSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_ea9dc59d-948f-4765-8a80-dc97edb402bb" xlink:to="loc_us-gaap_NumberOfReportableSegments_e5679146-6650-4c86-ac29-f25fdc934313" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillRollForward_9010386d-1948-44ee-a9a6-98179bf53058" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_ea9dc59d-948f-4765-8a80-dc97edb402bb" xlink:to="loc_us-gaap_GoodwillRollForward_9010386d-1948-44ee-a9a6-98179bf53058" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_fa9f8e4e-270a-4f6f-aa95-ae73caa50c08" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_9010386d-1948-44ee-a9a6-98179bf53058" xlink:to="loc_us-gaap_Goodwill_fa9f8e4e-270a-4f6f-aa95-ae73caa50c08" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_1494dd49-3b64-45b9-af28-fad6d31efef6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillForeignCurrencyTranslationGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_9010386d-1948-44ee-a9a6-98179bf53058" xlink:to="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_1494dd49-3b64-45b9-af28-fad6d31efef6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_4b0006a2-8aa7-482b-ae33-78483c181f12" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/FinancialLiabilitiesLoansandRCFAgreementsDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#FinancialLiabilitiesLoansandRCFAgreementsDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/FinancialLiabilitiesLoansandRCFAgreementsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_c931e3f8-b273-448d-8bf6-888b6c0fe8c3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_e758ba52-4271-4d89-9e32-538f68416c91" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c931e3f8-b273-448d-8bf6-888b6c0fe8c3" xlink:to="loc_us-gaap_DebtInstrumentTable_e758ba52-4271-4d89-9e32-538f68416c91" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_5c3c30dc-09c1-46fd-82ca-f6074d9ab50d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_e758ba52-4271-4d89-9e32-538f68416c91" xlink:to="loc_us-gaap_CreditFacilityAxis_5c3c30dc-09c1-46fd-82ca-f6074d9ab50d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_5c3c30dc-09c1-46fd-82ca-f6074d9ab50d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_5c3c30dc-09c1-46fd-82ca-f6074d9ab50d" xlink:to="loc_us-gaap_CreditFacilityDomain_5c3c30dc-09c1-46fd-82ca-f6074d9ab50d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_263d46e4-5cdd-4a02-8700-af273583b2d1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_5c3c30dc-09c1-46fd-82ca-f6074d9ab50d" xlink:to="loc_us-gaap_CreditFacilityDomain_263d46e4-5cdd-4a02-8700-af273583b2d1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_77532aa2-2c3e-4c8e-9926-de68b46c137f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_263d46e4-5cdd-4a02-8700-af273583b2d1" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_77532aa2-2c3e-4c8e-9926-de68b46c137f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_b5846039-a9d0-49a0-aea1-3a22f01c7afd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_263d46e4-5cdd-4a02-8700-af273583b2d1" xlink:to="loc_us-gaap_LineOfCreditMember_b5846039-a9d0-49a0-aea1-3a22f01c7afd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_09305f9b-d690-40d2-9aa0-6df13016a2eb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_e758ba52-4271-4d89-9e32-538f68416c91" xlink:to="loc_us-gaap_DebtInstrumentAxis_09305f9b-d690-40d2-9aa0-6df13016a2eb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_09305f9b-d690-40d2-9aa0-6df13016a2eb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_09305f9b-d690-40d2-9aa0-6df13016a2eb" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_09305f9b-d690-40d2-9aa0-6df13016a2eb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_c7054a6d-6b6d-412d-88b0-316541a9873e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_09305f9b-d690-40d2-9aa0-6df13016a2eb" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_c7054a6d-6b6d-412d-88b0-316541a9873e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_BankSyndicateRCFMember_6888e8ae-fed8-465d-919a-d434e0140d6a" xlink:href="crto-20251231.xsd#crto_BankSyndicateRCFMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c7054a6d-6b6d-412d-88b0-316541a9873e" xlink:to="loc_crto_BankSyndicateRCFMember_6888e8ae-fed8-465d-919a-d434e0140d6a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_HSBCandLCLFacilitiesMember_4c5cb7ec-d1d3-4277-8374-21fc356dc573" xlink:href="crto-20251231.xsd#crto_HSBCandLCLFacilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_c7054a6d-6b6d-412d-88b0-316541a9873e" xlink:to="loc_crto_HSBCandLCLFacilitiesMember_4c5cb7ec-d1d3-4277-8374-21fc356dc573" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_959ad047-0c09-46bf-bafe-45771efe25b4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_e758ba52-4271-4d89-9e32-538f68416c91" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_959ad047-0c09-46bf-bafe-45771efe25b4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_959ad047-0c09-46bf-bafe-45771efe25b4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_959ad047-0c09-46bf-bafe-45771efe25b4" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_959ad047-0c09-46bf-bafe-45771efe25b4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_1d31ecca-6e90-4149-97a2-bf85576b71aa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_959ad047-0c09-46bf-bafe-45771efe25b4" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_1d31ecca-6e90-4149-97a2-bf85576b71aa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_94cd140c-615d-401b-a103-13af2d0cddfb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_1d31ecca-6e90-4149-97a2-bf85576b71aa" xlink:to="loc_us-gaap_LineOfCreditMember_94cd140c-615d-401b-a103-13af2d0cddfb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtTypeAxis_d69f5e31-3836-4632-a3ce-4ac36566d748" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShortTermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_e758ba52-4271-4d89-9e32-538f68416c91" xlink:to="loc_us-gaap_ShortTermDebtTypeAxis_d69f5e31-3836-4632-a3ce-4ac36566d748" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtTypeDomain_d69f5e31-3836-4632-a3ce-4ac36566d748_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShortTermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ShortTermDebtTypeAxis_d69f5e31-3836-4632-a3ce-4ac36566d748" xlink:to="loc_us-gaap_ShortTermDebtTypeDomain_d69f5e31-3836-4632-a3ce-4ac36566d748_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtTypeDomain_79b9cc3d-231b-4336-a4e5-18f1be13815f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShortTermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ShortTermDebtTypeAxis_d69f5e31-3836-4632-a3ce-4ac36566d748" xlink:to="loc_us-gaap_ShortTermDebtTypeDomain_79b9cc3d-231b-4336-a4e5-18f1be13815f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BankOverdraftsMember_89048e8e-8e47-4aae-a207-bda111dac5a0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BankOverdraftsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShortTermDebtTypeDomain_79b9cc3d-231b-4336-a4e5-18f1be13815f" xlink:to="loc_us-gaap_BankOverdraftsMember_89048e8e-8e47-4aae-a207-bda111dac5a0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_a5ed12a2-3ca5-4f48-b386-9ab238c6b5f3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c931e3f8-b273-448d-8bf6-888b6c0fe8c3" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_a5ed12a2-3ca5-4f48-b386-9ab238c6b5f3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_fbbcfc05-da92-464a-8dc6-e1b4eaeab13c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c931e3f8-b273-448d-8bf6-888b6c0fe8c3" xlink:to="loc_us-gaap_LongTermDebt_fbbcfc05-da92-464a-8dc6-e1b4eaeab13c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermBorrowings_6b241266-ca99-4746-ad6a-ca6d921fd393" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShortTermBorrowings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c931e3f8-b273-448d-8bf6-888b6c0fe8c3" xlink:to="loc_us-gaap_ShortTermBorrowings_6b241266-ca99-4746-ad6a-ca6d921fd393" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/FinancialLiabilitiesNarrativeDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#FinancialLiabilitiesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/FinancialLiabilitiesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_9f433c63-9f7a-44e9-b292-5b8c05dd0983" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_7173a01e-5ea7-400b-84ab-94dc0bf9abf2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9f433c63-9f7a-44e9-b292-5b8c05dd0983" xlink:to="loc_us-gaap_DebtInstrumentTable_7173a01e-5ea7-400b-84ab-94dc0bf9abf2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_3dff7269-ae77-4ebe-a475-6aa8be9e5861" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_7173a01e-5ea7-400b-84ab-94dc0bf9abf2" xlink:to="loc_us-gaap_CreditFacilityAxis_3dff7269-ae77-4ebe-a475-6aa8be9e5861" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_3dff7269-ae77-4ebe-a475-6aa8be9e5861_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_3dff7269-ae77-4ebe-a475-6aa8be9e5861" xlink:to="loc_us-gaap_CreditFacilityDomain_3dff7269-ae77-4ebe-a475-6aa8be9e5861_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_9b479cef-4947-45c8-b2b2-ca26287cba42" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_3dff7269-ae77-4ebe-a475-6aa8be9e5861" xlink:to="loc_us-gaap_CreditFacilityDomain_9b479cef-4947-45c8-b2b2-ca26287cba42" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_d1484d11-9756-446f-bca5-4abae56b363c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_9b479cef-4947-45c8-b2b2-ca26287cba42" xlink:to="loc_us-gaap_LineOfCreditMember_d1484d11-9756-446f-bca5-4abae56b363c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_1387f1c4-8921-4512-8859-acc85dfe0e02" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_7173a01e-5ea7-400b-84ab-94dc0bf9abf2" xlink:to="loc_us-gaap_DebtInstrumentAxis_1387f1c4-8921-4512-8859-acc85dfe0e02" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_1387f1c4-8921-4512-8859-acc85dfe0e02_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_1387f1c4-8921-4512-8859-acc85dfe0e02" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_1387f1c4-8921-4512-8859-acc85dfe0e02_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_db4680e9-df3d-4727-9a18-56d38f6a8434" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_1387f1c4-8921-4512-8859-acc85dfe0e02" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_db4680e9-df3d-4727-9a18-56d38f6a8434" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_BankSyndicateRCFMember_662e469a-d4cd-4594-9cfa-d80c51b6df44" xlink:href="crto-20251231.xsd#crto_BankSyndicateRCFMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_db4680e9-df3d-4727-9a18-56d38f6a8434" xlink:to="loc_crto_BankSyndicateRCFMember_662e469a-d4cd-4594-9cfa-d80c51b6df44" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_HSBCandLCLFacilitiesMember_3d8029c9-550e-4584-b92b-ce9edd0d054d" xlink:href="crto-20251231.xsd#crto_HSBCandLCLFacilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_db4680e9-df3d-4727-9a18-56d38f6a8434" xlink:to="loc_crto_HSBCandLCLFacilitiesMember_3d8029c9-550e-4584-b92b-ce9edd0d054d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_353da7ca-69d9-4029-aee6-621a68788dd1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_7173a01e-5ea7-400b-84ab-94dc0bf9abf2" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_353da7ca-69d9-4029-aee6-621a68788dd1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_353da7ca-69d9-4029-aee6-621a68788dd1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_353da7ca-69d9-4029-aee6-621a68788dd1" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_353da7ca-69d9-4029-aee6-621a68788dd1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_0551ed4d-120f-4303-8fd5-fa20a9040f72" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_353da7ca-69d9-4029-aee6-621a68788dd1" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_0551ed4d-120f-4303-8fd5-fa20a9040f72" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_1bbcadb7-f5ec-4442-b88a-7f13b15cce63" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_0551ed4d-120f-4303-8fd5-fa20a9040f72" xlink:to="loc_us-gaap_LineOfCreditMember_1bbcadb7-f5ec-4442-b88a-7f13b15cce63" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtTypeAxis_d2699e67-5889-4a54-bfab-5be7baefcfcd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShortTermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_7173a01e-5ea7-400b-84ab-94dc0bf9abf2" xlink:to="loc_us-gaap_ShortTermDebtTypeAxis_d2699e67-5889-4a54-bfab-5be7baefcfcd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtTypeDomain_d2699e67-5889-4a54-bfab-5be7baefcfcd_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShortTermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ShortTermDebtTypeAxis_d2699e67-5889-4a54-bfab-5be7baefcfcd" xlink:to="loc_us-gaap_ShortTermDebtTypeDomain_d2699e67-5889-4a54-bfab-5be7baefcfcd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShortTermDebtTypeDomain_ccbcec31-ab22-46d5-a2de-1995b376f48b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShortTermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ShortTermDebtTypeAxis_d2699e67-5889-4a54-bfab-5be7baefcfcd" xlink:to="loc_us-gaap_ShortTermDebtTypeDomain_ccbcec31-ab22-46d5-a2de-1995b376f48b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BankOverdraftsMember_c5cbc168-eaf9-4ea4-af43-2720cec0f88b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BankOverdraftsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShortTermDebtTypeDomain_ccbcec31-ab22-46d5-a2de-1995b376f48b" xlink:to="loc_us-gaap_BankOverdraftsMember_c5cbc168-eaf9-4ea4-af43-2720cec0f88b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_92887486-6dd9-4c12-92f6-150606d05d4f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9f433c63-9f7a-44e9-b292-5b8c05dd0983" xlink:to="loc_us-gaap_LongTermDebt_92887486-6dd9-4c12-92f6-150606d05d4f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_db78d9f1-c033-4e61-83fa-d36f40f75a05" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_9f433c63-9f7a-44e9-b292-5b8c05dd0983" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_db78d9f1-c033-4e61-83fa-d36f40f75a05" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/CommonsharesandTreasurystockDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#CommonsharesandTreasurystockDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/CommonsharesandTreasurystockDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_fce21835-6e0f-4368-afd3-14e62ae1297a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_333517b3-fa8a-43e3-8654-c86f11e647e6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_fce21835-6e0f-4368-afd3-14e62ae1297a" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_333517b3-fa8a-43e3-8654-c86f11e647e6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_2171aa26-e33a-4ac3-ba87-82a0ba4a8364" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_333517b3-fa8a-43e3-8654-c86f11e647e6" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_2171aa26-e33a-4ac3-ba87-82a0ba4a8364" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_2171aa26-e33a-4ac3-ba87-82a0ba4a8364_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_2171aa26-e33a-4ac3-ba87-82a0ba4a8364" xlink:to="loc_us-gaap_EquityComponentDomain_2171aa26-e33a-4ac3-ba87-82a0ba4a8364_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_f8c57b69-ea45-4730-afed-28ca430c1c39" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_2171aa26-e33a-4ac3-ba87-82a0ba4a8364" xlink:to="loc_us-gaap_EquityComponentDomain_f8c57b69-ea45-4730-afed-28ca430c1c39" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_ac32676b-8279-4ad8-a880-4ccee7e45241" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_f8c57b69-ea45-4730-afed-28ca430c1c39" xlink:to="loc_us-gaap_CommonStockMember_ac32676b-8279-4ad8-a880-4ccee7e45241" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonMember_870977e4-822f-4032-b25a-65a1386ab528" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockCommonMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_f8c57b69-ea45-4730-afed-28ca430c1c39" xlink:to="loc_us-gaap_TreasuryStockCommonMember_870977e4-822f-4032-b25a-65a1386ab528" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_63533c4b-355a-476c-ac98-bd89233b0f5e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_333517b3-fa8a-43e3-8654-c86f11e647e6" xlink:to="loc_us-gaap_AwardTypeAxis_63533c4b-355a-476c-ac98-bd89233b0f5e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_63533c4b-355a-476c-ac98-bd89233b0f5e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_63533c4b-355a-476c-ac98-bd89233b0f5e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_63533c4b-355a-476c-ac98-bd89233b0f5e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_8cbb5cfe-7441-46e0-b973-01f1e039a5f5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_63533c4b-355a-476c-ac98-bd89233b0f5e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_8cbb5cfe-7441-46e0-b973-01f1e039a5f5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_c7186628-755e-4b6c-bf87-ff25993a1176" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_8cbb5cfe-7441-46e0-b973-01f1e039a5f5" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_c7186628-755e-4b6c-bf87-ff25993a1176" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_LockUpSharesLUSsMember_1c2da958-6f67-4274-b1d0-afcf5573c522" xlink:href="crto-20251231.xsd#crto_LockUpSharesLUSsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_8cbb5cfe-7441-46e0-b973-01f1e039a5f5" xlink:to="loc_crto_LockUpSharesLUSsMember_1c2da958-6f67-4274-b1d0-afcf5573c522" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CommonStockSharesOutstandingRollForward_1d197bc7-1527-4215-b926-417ae93e1f9d" xlink:href="crto-20251231.xsd#crto_CommonStockSharesOutstandingRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_fce21835-6e0f-4368-afd3-14e62ae1297a" xlink:to="loc_crto_CommonStockSharesOutstandingRollForward_1d197bc7-1527-4215-b926-417ae93e1f9d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesOutstanding_79201a4b-b333-4ce7-97fb-a22101967642" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_crto_CommonStockSharesOutstandingRollForward_1d197bc7-1527-4215-b926-417ae93e1f9d" xlink:to="loc_us-gaap_SharesOutstanding_79201a4b-b333-4ce7-97fb-a22101967642" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonShares_43358f8b-7ea2-4809-961d-9fc68a7ade25" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockCommonShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_crto_CommonStockSharesOutstandingRollForward_1d197bc7-1527-4215-b926-417ae93e1f9d" xlink:to="loc_us-gaap_TreasuryStockCommonShares_43358f8b-7ea2-4809-961d-9fc68a7ade25" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_ef8f3087-04f5-468f-a27c-5c12fb585ade" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_crto_CommonStockSharesOutstandingRollForward_1d197bc7-1527-4215-b926-417ae93e1f9d" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_ef8f3087-04f5-468f-a27c-5c12fb585ade" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesTreasuryStockReissued_891bcdf7-7387-4fec-8ca0-03a6ece44d78" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesTreasuryStockReissued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_crto_CommonStockSharesOutstandingRollForward_1d197bc7-1527-4215-b926-417ae93e1f9d" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesTreasuryStockReissued_891bcdf7-7387-4fec-8ca0-03a6ece44d78" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockSharesRetired_8d1ecde7-81a3-44c8-9c02-dcd59acbca65" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockSharesRetired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_crto_CommonStockSharesOutstandingRollForward_1d197bc7-1527-4215-b926-417ae93e1f9d" xlink:to="loc_us-gaap_TreasuryStockSharesRetired_8d1ecde7-81a3-44c8-9c02-dcd59acbca65" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_da603b1d-8512-4b90-acd5-d44faaf37d18" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockSharesAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_crto_CommonStockSharesOutstandingRollForward_1d197bc7-1527-4215-b926-417ae93e1f9d" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_da603b1d-8512-4b90-acd5-d44faaf37d18" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesOutstanding_fae1630c-f463-4afc-a986-cb0f9ea95b30" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonShares_a19ce92f-65f0-4534-bc91-8335d41afc6c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockCommonShares"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonShares_dbab96f6-16f3-4c1e-bfb3-dce8092046c1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockCommonShares"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/ShareBasedCompensationEquityAwardsCompensationExpenseDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#ShareBasedCompensationEquityAwardsCompensationExpenseDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/ShareBasedCompensationEquityAwardsCompensationExpenseDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_4c19e6ae-6e8c-4af3-98c7-d77aa0f06f62" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_45b574d1-e474-48af-b515-0ce8d62a54ab" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_4c19e6ae-6e8c-4af3-98c7-d77aa0f06f62" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_45b574d1-e474-48af-b515-0ce8d62a54ab" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_2d68676e-e493-4fd0-99de-32360f1a98b8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_45b574d1-e474-48af-b515-0ce8d62a54ab" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_2d68676e-e493-4fd0-99de-32360f1a98b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_2d68676e-e493-4fd0-99de-32360f1a98b8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_2d68676e-e493-4fd0-99de-32360f1a98b8" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_2d68676e-e493-4fd0-99de-32360f1a98b8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_f4a9b7a8-2b5b-48a3-9722-65f7ee5c3e04" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_2d68676e-e493-4fd0-99de-32360f1a98b8" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_f4a9b7a8-2b5b-48a3-9722-65f7ee5c3e04" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpenseMember_34a9e65e-bd4b-492c-97a3-3593346fea85" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResearchAndDevelopmentExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_f4a9b7a8-2b5b-48a3-9722-65f7ee5c3e04" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpenseMember_34a9e65e-bd4b-492c-97a3-3593346fea85" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_SalesAndOperationsExpenseMember_8d218b8a-d493-4dc8-898f-9c2eef5f111c" xlink:href="crto-20251231.xsd#crto_SalesAndOperationsExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_f4a9b7a8-2b5b-48a3-9722-65f7ee5c3e04" xlink:to="loc_crto_SalesAndOperationsExpenseMember_8d218b8a-d493-4dc8-898f-9c2eef5f111c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpenseMember_a26da3eb-9240-48d2-878a-cda57ce60fb4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeneralAndAdministrativeExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_f4a9b7a8-2b5b-48a3-9722-65f7ee5c3e04" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpenseMember_a26da3eb-9240-48d2-878a-cda57ce60fb4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_1b347932-37e3-4988-b3c6-c01ff9b2c53f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_45b574d1-e474-48af-b515-0ce8d62a54ab" xlink:to="loc_us-gaap_AwardTypeAxis_1b347932-37e3-4988-b3c6-c01ff9b2c53f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1b347932-37e3-4988-b3c6-c01ff9b2c53f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_1b347932-37e3-4988-b3c6-c01ff9b2c53f" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1b347932-37e3-4988-b3c6-c01ff9b2c53f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_5f78cab9-694a-4f18-b7b3-fcc9eb871567" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_1b347932-37e3-4988-b3c6-c01ff9b2c53f" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_5f78cab9-694a-4f18-b7b3-fcc9eb871567" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_RestrictedStockUnitRSUsAndPerformanceSharesUnitsPSUsMember_385c5eed-32e5-47f3-9061-262d8768bfab" xlink:href="crto-20251231.xsd#crto_RestrictedStockUnitRSUsAndPerformanceSharesUnitsPSUsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_5f78cab9-694a-4f18-b7b3-fcc9eb871567" xlink:to="loc_crto_RestrictedStockUnitRSUsAndPerformanceSharesUnitsPSUsMember_385c5eed-32e5-47f3-9061-262d8768bfab" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_LockUpSharesLUSsMember_910664f6-62e5-44c5-80fb-1bec54f7a657" xlink:href="crto-20251231.xsd#crto_LockUpSharesLUSsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_5f78cab9-694a-4f18-b7b3-fcc9eb871567" xlink:to="loc_crto_LockUpSharesLUSsMember_910664f6-62e5-44c5-80fb-1bec54f7a657" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_NonEmployeeWarrantMember_d268b45a-abf1-4b34-b514-4585c6c162b0" xlink:href="crto-20251231.xsd#crto_NonEmployeeWarrantMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_5f78cab9-694a-4f18-b7b3-fcc9eb871567" xlink:to="loc_crto_NonEmployeeWarrantMember_d268b45a-abf1-4b34-b514-4585c6c162b0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_043ca0ee-0e84-491a-9fa6-8aa16a0714cb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_5f78cab9-694a-4f18-b7b3-fcc9eb871567" xlink:to="loc_us-gaap_EmployeeStockOptionMember_043ca0ee-0e84-491a-9fa6-8aa16a0714cb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_06a9c382-0a0a-4f1d-9c7b-b63ecb9575ef" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_4c19e6ae-6e8c-4af3-98c7-d77aa0f06f62" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_06a9c382-0a0a-4f1d-9c7b-b63ecb9575ef" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_f1799b89-27fd-47d3-af4a-ba929a6cbd72" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_4c19e6ae-6e8c-4af3-98c7-d77aa0f06f62" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_f1799b89-27fd-47d3-af4a-ba929a6cbd72" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax_3a6c5731-41e3-4599-a777-6c3af87b3a03" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_4c19e6ae-6e8c-4af3-98c7-d77aa0f06f62" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpenseNetOfTax_3a6c5731-41e3-4599-a777-6c3af87b3a03" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount_9ec66142-8388-485b-b5b0-51fe961adfdd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_4c19e6ae-6e8c-4af3-98c7-d77aa0f06f62" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsCapitalizedAmount_9ec66142-8388-485b-b5b0-51fe961adfdd" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/ShareBasedCompensationNarrativeDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#ShareBasedCompensationNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/ShareBasedCompensationNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a4a1a48a-98ba-4839-add0-aaba4a8d6baf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_a4158edc-cb0d-4fd6-b6b6-e9f22f6d298e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a4a1a48a-98ba-4839-add0-aaba4a8d6baf" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_a4158edc-cb0d-4fd6-b6b6-e9f22f6d298e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_82845c87-f6fd-4bdc-920e-d110d0dbcb12" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_a4158edc-cb0d-4fd6-b6b6-e9f22f6d298e" xlink:to="loc_us-gaap_AwardTypeAxis_82845c87-f6fd-4bdc-920e-d110d0dbcb12" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_82845c87-f6fd-4bdc-920e-d110d0dbcb12_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_82845c87-f6fd-4bdc-920e-d110d0dbcb12" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_82845c87-f6fd-4bdc-920e-d110d0dbcb12_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1e2d1a5e-dbe7-42dd-adad-b65418e2fbed" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_82845c87-f6fd-4bdc-920e-d110d0dbcb12" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1e2d1a5e-dbe7-42dd-adad-b65418e2fbed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_23e7f905-ea34-439d-b0ad-24c1a15d5852" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1e2d1a5e-dbe7-42dd-adad-b65418e2fbed" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_23e7f905-ea34-439d-b0ad-24c1a15d5852" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_FinancialPerformanceSharesUnitsMember_b0a865f1-4544-4725-986e-f628ba2db0d1" xlink:href="crto-20251231.xsd#crto_FinancialPerformanceSharesUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1e2d1a5e-dbe7-42dd-adad-b65418e2fbed" xlink:to="loc_crto_FinancialPerformanceSharesUnitsMember_b0a865f1-4544-4725-986e-f628ba2db0d1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_TotalShareholderReturnTSRMember_d6d38c07-8785-4b83-9535-739d0ce80edd" xlink:href="crto-20251231.xsd#crto_TotalShareholderReturnTSRMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1e2d1a5e-dbe7-42dd-adad-b65418e2fbed" xlink:to="loc_crto_TotalShareholderReturnTSRMember_d6d38c07-8785-4b83-9535-739d0ce80edd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_TotalShareholderReturnPSUsMember_019c332d-2f2e-7c52-80ba-a0caebc057bd" xlink:href="crto-20251231.xsd#crto_TotalShareholderReturnPSUsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1e2d1a5e-dbe7-42dd-adad-b65418e2fbed" xlink:to="loc_crto_TotalShareholderReturnPSUsMember_019c332d-2f2e-7c52-80ba-a0caebc057bd" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_LockUpSharesLUSsMember_4053e664-8ec7-4aa8-82de-2e3690fe6d68" xlink:href="crto-20251231.xsd#crto_LockUpSharesLUSsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1e2d1a5e-dbe7-42dd-adad-b65418e2fbed" xlink:to="loc_crto_LockUpSharesLUSsMember_4053e664-8ec7-4aa8-82de-2e3690fe6d68" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_NonEmployeeWarrantMember_c1915831-c502-4c04-95a8-81fad0f09a9f" xlink:href="crto-20251231.xsd#crto_NonEmployeeWarrantMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1e2d1a5e-dbe7-42dd-adad-b65418e2fbed" xlink:to="loc_crto_NonEmployeeWarrantMember_c1915831-c502-4c04-95a8-81fad0f09a9f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_a1d9bcaf-7eee-4bc4-862e-49bcf5f839a5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1e2d1a5e-dbe7-42dd-adad-b65418e2fbed" xlink:to="loc_us-gaap_EmployeeStockOptionMember_a1d9bcaf-7eee-4bc4-862e-49bcf5f839a5" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingAxis_1cacf7e1-e7b2-4a5f-8036-8a440f7c1adf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VestingAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_a4158edc-cb0d-4fd6-b6b6-e9f22f6d298e" xlink:to="loc_us-gaap_VestingAxis_1cacf7e1-e7b2-4a5f-8036-8a440f7c1adf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingDomain_1cacf7e1-e7b2-4a5f-8036-8a440f7c1adf_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VestingDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VestingAxis_1cacf7e1-e7b2-4a5f-8036-8a440f7c1adf" xlink:to="loc_us-gaap_VestingDomain_1cacf7e1-e7b2-4a5f-8036-8a440f7c1adf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingDomain_5a161baa-f5f5-4f33-9130-9ef3f7f2bd65" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VestingDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VestingAxis_1cacf7e1-e7b2-4a5f-8036-8a440f7c1adf" xlink:to="loc_us-gaap_VestingDomain_5a161baa-f5f5-4f33-9130-9ef3f7f2bd65" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheOneMember_fd762579-2be2-40ac-8c81-043d28f8cc7c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationAwardTrancheOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VestingDomain_5a161baa-f5f5-4f33-9130-9ef3f7f2bd65" xlink:to="loc_us-gaap_ShareBasedCompensationAwardTrancheOneMember_fd762579-2be2-40ac-8c81-043d28f8cc7c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheTwoMember_600e0f78-79b7-4a03-b6e4-363928e71bcc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationAwardTrancheTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VestingDomain_5a161baa-f5f5-4f33-9130-9ef3f7f2bd65" xlink:to="loc_us-gaap_ShareBasedCompensationAwardTrancheTwoMember_600e0f78-79b7-4a03-b6e4-363928e71bcc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_24d27fd4-8307-4954-9e4f-1290fe1826da" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_a4158edc-cb0d-4fd6-b6b6-e9f22f6d298e" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_24d27fd4-8307-4954-9e4f-1290fe1826da" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_24d27fd4-8307-4954-9e4f-1290fe1826da_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_24d27fd4-8307-4954-9e4f-1290fe1826da" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_24d27fd4-8307-4954-9e4f-1290fe1826da_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_97a0018c-85fc-4ab7-9cf1-1873e9851016" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_24d27fd4-8307-4954-9e4f-1290fe1826da" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_97a0018c-85fc-4ab7-9cf1-1873e9851016" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralAndAdministrativeExpenseMember_019c2e57-aa00-7a66-b592-233c4cf62465" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeneralAndAdministrativeExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_97a0018c-85fc-4ab7-9cf1-1873e9851016" xlink:to="loc_us-gaap_GeneralAndAdministrativeExpenseMember_019c2e57-aa00-7a66-b592-233c4cf62465" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_SalesAndOperationsExpenseMember_019c2e58-939f-7150-8e6f-5c5c446e965b" xlink:href="crto-20251231.xsd#crto_SalesAndOperationsExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_97a0018c-85fc-4ab7-9cf1-1873e9851016" xlink:to="loc_crto_SalesAndOperationsExpenseMember_019c2e58-939f-7150-8e6f-5c5c446e965b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ChangeInAccountingEstimateByTypeAxis_019c3904-b567-7ac4-b82b-08cfb957db01" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ChangeInAccountingEstimateByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_a4158edc-cb0d-4fd6-b6b6-e9f22f6d298e" xlink:to="loc_us-gaap_ChangeInAccountingEstimateByTypeAxis_019c3904-b567-7ac4-b82b-08cfb957db01" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ChangeInAccountingEstimateTypeDomain_019c3904-b567-7ac4-b82b-08cfb957db01_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ChangeInAccountingEstimateTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ChangeInAccountingEstimateByTypeAxis_019c3904-b567-7ac4-b82b-08cfb957db01" xlink:to="loc_us-gaap_ChangeInAccountingEstimateTypeDomain_019c3904-b567-7ac4-b82b-08cfb957db01_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ChangeInAccountingEstimateTypeDomain_019c3904-b567-73e2-a929-5979239bd5a4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ChangeInAccountingEstimateTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ChangeInAccountingEstimateByTypeAxis_019c3904-b567-7ac4-b82b-08cfb957db01" xlink:to="loc_us-gaap_ChangeInAccountingEstimateTypeDomain_019c3904-b567-73e2-a929-5979239bd5a4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_VestingTermsOfPerformanceStockUnitsMember_019c3904-b567-7ad2-8fd9-ad7de77b1349" xlink:href="crto-20251231.xsd#crto_VestingTermsOfPerformanceStockUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ChangeInAccountingEstimateTypeDomain_019c3904-b567-73e2-a929-5979239bd5a4" xlink:to="loc_crto_VestingTermsOfPerformanceStockUnitsMember_019c3904-b567-7ad2-8fd9-ad7de77b1349" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_ShareBasedPaymentArrangementReversalOfExpense_019c2e59-7093-7aef-ac0e-3561b2c0c1c9" xlink:href="crto-20251231.xsd#crto_ShareBasedPaymentArrangementReversalOfExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a4a1a48a-98ba-4839-add0-aaba4a8d6baf" xlink:to="loc_crto_ShareBasedPaymentArrangementReversalOfExpense_019c2e59-7093-7aef-ac0e-3561b2c0c1c9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_85425fa5-3ae1-4a43-8096-aaa7439466fa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a4a1a48a-98ba-4839-add0-aaba4a8d6baf" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_85425fa5-3ae1-4a43-8096-aaa7439466fa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_7aab00ab-6fe5-474e-9f68-749187ee0da3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a4a1a48a-98ba-4839-add0-aaba4a8d6baf" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_7aab00ab-6fe5-474e-9f68-749187ee0da3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_88b0d8ef-8450-40f6-905b-c3b83da31156" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a4a1a48a-98ba-4839-add0-aaba4a8d6baf" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_88b0d8ef-8450-40f6-905b-c3b83da31156" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_4df015be-b758-4d63-ad43-bf3930861b3f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a4a1a48a-98ba-4839-add0-aaba4a8d6baf" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_4df015be-b758-4d63-ad43-bf3930861b3f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_43f578d9-3131-4b26-97e4-c2ad02cd638d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a4a1a48a-98ba-4839-add0-aaba4a8d6baf" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_43f578d9-3131-4b26-97e4-c2ad02cd638d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_ShareBasedCompensationArrangementByShareBasedPaymentAwardMinimumPercentageIncreaseToTargetShares_865d4780-9a23-42ce-a2ee-49d3ee776a9e" xlink:href="crto-20251231.xsd#crto_ShareBasedCompensationArrangementByShareBasedPaymentAwardMinimumPercentageIncreaseToTargetShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a4a1a48a-98ba-4839-add0-aaba4a8d6baf" xlink:to="loc_crto_ShareBasedCompensationArrangementByShareBasedPaymentAwardMinimumPercentageIncreaseToTargetShares_865d4780-9a23-42ce-a2ee-49d3ee776a9e" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumPercentageIncreaseToTargetShares_db419bb5-309a-4e70-91af-d2592f54baf7" xlink:href="crto-20251231.xsd#crto_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumPercentageIncreaseToTargetShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a4a1a48a-98ba-4839-add0-aaba4a8d6baf" xlink:to="loc_crto_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumPercentageIncreaseToTargetShares_db419bb5-309a-4e70-91af-d2592f54baf7" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumTargetShares_73e523a2-a000-463b-bb14-5f72c36851d5" xlink:href="crto-20251231.xsd#crto_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumTargetShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a4a1a48a-98ba-4839-add0-aaba4a8d6baf" xlink:to="loc_crto_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumTargetShares_73e523a2-a000-463b-bb14-5f72c36851d5" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodGrantDateFairValue_18b9927f-b883-4380-a4e7-b32a45a2e5e9" xlink:href="crto-20251231.xsd#crto_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a4a1a48a-98ba-4839-add0-aaba4a8d6baf" xlink:to="loc_crto_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodGrantDateFairValue_18b9927f-b883-4380-a4e7-b32a45a2e5e9" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_NumberOfTranches_42a1455d-3663-46fa-aec2-e7cdb4bfade2" xlink:href="crto-20251231.xsd#crto_NumberOfTranches"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a4a1a48a-98ba-4839-add0-aaba4a8d6baf" xlink:to="loc_crto_NumberOfTranches_42a1455d-3663-46fa-aec2-e7cdb4bfade2" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_ShareBasedCompensationArrangementModificationServicePeriod_019c750c-b1ef-7f29-a7bf-9c6c577258dc" xlink:href="crto-20251231.xsd#crto_ShareBasedCompensationArrangementModificationServicePeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a4a1a48a-98ba-4839-add0-aaba4a8d6baf" xlink:to="loc_crto_ShareBasedCompensationArrangementModificationServicePeriod_019c750c-b1ef-7f29-a7bf-9c6c577258dc" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_NumberOfGranteesAffectedByShareBasedCompensationModification_019c7514-4d6f-724c-bd67-f174141cf217" xlink:href="crto-20251231.xsd#crto_NumberOfGranteesAffectedByShareBasedCompensationModification"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a4a1a48a-98ba-4839-add0-aaba4a8d6baf" xlink:to="loc_crto_NumberOfGranteesAffectedByShareBasedCompensationModification_019c7514-4d6f-724c-bd67-f174141cf217" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019c3330-b797-7890-9001-3fdd6fdd4dc3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a4a1a48a-98ba-4839-add0-aaba4a8d6baf" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019c3330-b797-7890-9001-3fdd6fdd4dc3" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WarrantsAndRightsOutstandingTerm_d2923483-d1c3-4751-9dc7-c34ba17943c4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_WarrantsAndRightsOutstandingTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a4a1a48a-98ba-4839-add0-aaba4a8d6baf" xlink:to="loc_us-gaap_WarrantsAndRightsOutstandingTerm_d2923483-d1c3-4751-9dc7-c34ba17943c4" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_ClassOfWarrantOrRightExercisedDuringPeriod_1bb2b045-1740-46b7-9c7b-ccd7caaf1466" xlink:href="crto-20251231.xsd#crto_ClassOfWarrantOrRightExercisedDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a4a1a48a-98ba-4839-add0-aaba4a8d6baf" xlink:to="loc_crto_ClassOfWarrantOrRightExercisedDuringPeriod_1bb2b045-1740-46b7-9c7b-ccd7caaf1466" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_ClassOfWarrantOrRightGrantedDuringPeriod_3afbbb10-1e52-4804-a6b4-0e1b03f60ae4" xlink:href="crto-20251231.xsd#crto_ClassOfWarrantOrRightGrantedDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a4a1a48a-98ba-4839-add0-aaba4a8d6baf" xlink:to="loc_crto_ClassOfWarrantOrRightGrantedDuringPeriod_3afbbb10-1e52-4804-a6b4-0e1b03f60ae4" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_7c736f9a-08c3-415d-95ab-f77374c9229b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a4a1a48a-98ba-4839-add0-aaba4a8d6baf" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_7c736f9a-08c3-415d-95ab-f77374c9229b" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_88ba49b8-3bc4-4671-99c0-7aac8b49d0a2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a4a1a48a-98ba-4839-add0-aaba4a8d6baf" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_88ba49b8-3bc4-4671-99c0-7aac8b49d0a2" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_fd19ffe2-a805-4ff0-8188-43f9cb465712" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a4a1a48a-98ba-4839-add0-aaba4a8d6baf" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_fd19ffe2-a805-4ff0-8188-43f9cb465712" xlink:type="arc" order="19"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/ShareBasedCompensationRSUActivityDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#ShareBasedCompensationRSUActivityDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/ShareBasedCompensationRSUActivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_e38ac124-65b0-4d81-a2e8-7b7cb56076df" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_89c3a8ac-0dc5-4821-bfad-23f0258d00f3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_e38ac124-65b0-4d81-a2e8-7b7cb56076df" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_89c3a8ac-0dc5-4821-bfad-23f0258d00f3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_1c08c454-5150-4ecf-8409-dccfd915c139" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_89c3a8ac-0dc5-4821-bfad-23f0258d00f3" xlink:to="loc_us-gaap_AwardTypeAxis_1c08c454-5150-4ecf-8409-dccfd915c139" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1c08c454-5150-4ecf-8409-dccfd915c139_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_1c08c454-5150-4ecf-8409-dccfd915c139" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1c08c454-5150-4ecf-8409-dccfd915c139_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_25d9972e-f91f-4912-94ea-40bb6c90e490" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_1c08c454-5150-4ecf-8409-dccfd915c139" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_25d9972e-f91f-4912-94ea-40bb6c90e490" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_6e8b2c68-6eb8-4232-93b0-db281af7b65b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_25d9972e-f91f-4912-94ea-40bb6c90e490" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_6e8b2c68-6eb8-4232-93b0-db281af7b65b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_35090ffe-c9fa-4744-b7ab-58d733ff1cf8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_e38ac124-65b0-4d81-a2e8-7b7cb56076df" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_35090ffe-c9fa-4744-b7ab-58d733ff1cf8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_fa1ecc55-6a02-4fc5-8cce-416d54b228f1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_35090ffe-c9fa-4744-b7ab-58d733ff1cf8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_fa1ecc55-6a02-4fc5-8cce-416d54b228f1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_2e613a69-6f39-4704-9f9a-5002c38dd118" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_35090ffe-c9fa-4744-b7ab-58d733ff1cf8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_2e613a69-6f39-4704-9f9a-5002c38dd118" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_0f51acd8-62bf-4040-b705-42632b02dc4c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_35090ffe-c9fa-4744-b7ab-58d733ff1cf8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_0f51acd8-62bf-4040-b705-42632b02dc4c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_f841765a-a4c1-4dd3-834e-6b20e9e2d3f0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_35090ffe-c9fa-4744-b7ab-58d733ff1cf8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_f841765a-a4c1-4dd3-834e-6b20e9e2d3f0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_1a0f9800-5c41-4fdd-9be3-a64b3ea4dd4f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_be0bdb92-4467-4788-a4c2-7deb81d12da3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_e38ac124-65b0-4d81-a2e8-7b7cb56076df" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_be0bdb92-4467-4788-a4c2-7deb81d12da3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019c2472-ebf5-7d68-b52b-6f265dae08b9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_be0bdb92-4467-4788-a4c2-7deb81d12da3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019c2472-ebf5-7d68-b52b-6f265dae08b9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019c246e-093e-7ab5-a3b1-22e971425ac5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_be0bdb92-4467-4788-a4c2-7deb81d12da3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019c246e-093e-7ab5-a3b1-22e971425ac5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019c2471-02e8-7cd9-ab86-a67293987895" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_be0bdb92-4467-4788-a4c2-7deb81d12da3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019c2471-02e8-7cd9-ab86-a67293987895" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019c2471-53e4-7f6f-b9dc-86946329b4c2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_be0bdb92-4467-4788-a4c2-7deb81d12da3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019c2471-53e4-7f6f-b9dc-86946329b4c2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_d69606f6-982a-48dd-a760-b2a00cb1f07f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/ShareBasedCompensationPSUActivityDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#ShareBasedCompensationPSUActivityDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/ShareBasedCompensationPSUActivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_85d4706c-6b89-4a96-bd06-cb8a1b020c0a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_2e882006-fb19-47cb-b62b-048a3f1ae20c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_85d4706c-6b89-4a96-bd06-cb8a1b020c0a" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_2e882006-fb19-47cb-b62b-048a3f1ae20c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_fe056fce-76f9-4984-ba29-16ef2dc0b69c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_2e882006-fb19-47cb-b62b-048a3f1ae20c" xlink:to="loc_us-gaap_AwardTypeAxis_fe056fce-76f9-4984-ba29-16ef2dc0b69c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_fe056fce-76f9-4984-ba29-16ef2dc0b69c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_fe056fce-76f9-4984-ba29-16ef2dc0b69c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_fe056fce-76f9-4984-ba29-16ef2dc0b69c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7108f898-aac8-4042-85ca-a2906a4d029c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_fe056fce-76f9-4984-ba29-16ef2dc0b69c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7108f898-aac8-4042-85ca-a2906a4d029c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_FinancialPerformanceSharesUnitsMember_52c742ee-0d54-4fcf-8b0b-ac6d04ac7fd0" xlink:href="crto-20251231.xsd#crto_FinancialPerformanceSharesUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7108f898-aac8-4042-85ca-a2906a4d029c" xlink:to="loc_crto_FinancialPerformanceSharesUnitsMember_52c742ee-0d54-4fcf-8b0b-ac6d04ac7fd0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_3d5ee34b-6673-46ff-8189-cf3d9412adbc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_85d4706c-6b89-4a96-bd06-cb8a1b020c0a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_3d5ee34b-6673-46ff-8189-cf3d9412adbc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_58dd4fce-d6e0-44d7-8ec5-0bf27d1c3511" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_3d5ee34b-6673-46ff-8189-cf3d9412adbc" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_58dd4fce-d6e0-44d7-8ec5-0bf27d1c3511" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_ab3dc425-ba67-4c79-819f-33429409c82a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_3d5ee34b-6673-46ff-8189-cf3d9412adbc" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_ab3dc425-ba67-4c79-819f-33429409c82a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdjustment_875de8a6-ed62-4183-9c8b-d940ba497500" xlink:href="crto-20251231.xsd#crto_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdjustment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_3d5ee34b-6673-46ff-8189-cf3d9412adbc" xlink:to="loc_crto_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdjustment_875de8a6-ed62-4183-9c8b-d940ba497500" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_88dbb661-103a-4bef-ae10-00c53e07ded8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_3d5ee34b-6673-46ff-8189-cf3d9412adbc" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_88dbb661-103a-4bef-ae10-00c53e07ded8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_35d54e45-270d-446a-a6d6-c00949e08665" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_3d5ee34b-6673-46ff-8189-cf3d9412adbc" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_35d54e45-270d-446a-a6d6-c00949e08665" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_38f6aaf3-4b6d-45de-888e-95bee9e96011" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_a2f86ff3-4287-46c9-afbb-0b4ee4a54116" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_85d4706c-6b89-4a96-bd06-cb8a1b020c0a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_a2f86ff3-4287-46c9-afbb-0b4ee4a54116" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019c2def-5239-70c6-829e-7c8fa8d40168" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_a2f86ff3-4287-46c9-afbb-0b4ee4a54116" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019c2def-5239-70c6-829e-7c8fa8d40168" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019c2dee-ddd4-72df-87cb-41999311f4d3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_a2f86ff3-4287-46c9-afbb-0b4ee4a54116" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019c2dee-ddd4-72df-87cb-41999311f4d3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdjustmentWeightedAverageGrantDateFairValue_019c2df0-b4a2-716f-9300-54b5259f69a3" xlink:href="crto-20251231.xsd#crto_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdjustmentWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_a2f86ff3-4287-46c9-afbb-0b4ee4a54116" xlink:to="loc_crto_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdjustmentWeightedAverageGrantDateFairValue_019c2df0-b4a2-716f-9300-54b5259f69a3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019c2df1-632f-76e2-85e7-59e99e1456ff" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_a2f86ff3-4287-46c9-afbb-0b4ee4a54116" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019c2df1-632f-76e2-85e7-59e99e1456ff" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019c2df1-a306-7ce1-8774-0d60dc2cf5d5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_a2f86ff3-4287-46c9-afbb-0b4ee4a54116" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019c2df1-a306-7ce1-8774-0d60dc2cf5d5" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_5a34c62a-d540-40da-9f3d-a92da8482d87" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/ShareBasedCompensationPerformanceStockUnitsTotalShareholderReturnActivityDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#ShareBasedCompensationPerformanceStockUnitsTotalShareholderReturnActivityDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/ShareBasedCompensationPerformanceStockUnitsTotalShareholderReturnActivityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_4f9a99f5-05b7-4bc9-b172-e72bf1c5c280" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_dcfe1379-6c55-4d9e-a3a1-02c6d6e86496" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_4f9a99f5-05b7-4bc9-b172-e72bf1c5c280" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_dcfe1379-6c55-4d9e-a3a1-02c6d6e86496" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_e3e45bb4-b6da-4f9e-b452-5338d65c9ab1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable_dcfe1379-6c55-4d9e-a3a1-02c6d6e86496" xlink:to="loc_us-gaap_AwardTypeAxis_e3e45bb4-b6da-4f9e-b452-5338d65c9ab1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_e3e45bb4-b6da-4f9e-b452-5338d65c9ab1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_e3e45bb4-b6da-4f9e-b452-5338d65c9ab1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_e3e45bb4-b6da-4f9e-b452-5338d65c9ab1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_b5934cac-f7f7-4f5e-bf1c-1b53d21a00dd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_e3e45bb4-b6da-4f9e-b452-5338d65c9ab1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_b5934cac-f7f7-4f5e-bf1c-1b53d21a00dd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_TotalShareholderReturnTSRMember_d6576721-b725-495e-8759-6537a43620fc" xlink:href="crto-20251231.xsd#crto_TotalShareholderReturnTSRMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_b5934cac-f7f7-4f5e-bf1c-1b53d21a00dd" xlink:to="loc_crto_TotalShareholderReturnTSRMember_d6576721-b725-495e-8759-6537a43620fc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateCompany_eff5f3ce-7fb1-428b-85ec-e22df3877b31" xlink:href="crto-20251231.xsd#crto_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_4f9a99f5-05b7-4bc9-b172-e72bf1c5c280" xlink:to="loc_crto_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateCompany_eff5f3ce-7fb1-428b-85ec-e22df3877b31" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateBenchmark_950b7d73-ff43-478d-ab26-f6445b35802e" xlink:href="crto-20251231.xsd#crto_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateBenchmark"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_4f9a99f5-05b7-4bc9-b172-e72bf1c5c280" xlink:to="loc_crto_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateBenchmark_950b7d73-ff43-478d-ab26-f6445b35802e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_5bf73dd4-e4ee-4839-b87e-7b0ab12decf6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_4f9a99f5-05b7-4bc9-b172-e72bf1c5c280" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_5bf73dd4-e4ee-4839-b87e-7b0ab12decf6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_40767b5d-c9dc-4786-af7b-4fd29e340c15" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_4f9a99f5-05b7-4bc9-b172-e72bf1c5c280" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate_40767b5d-c9dc-4786-af7b-4fd29e340c15" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_d3ac741f-9cd1-4e09-adc6-decae5b11dd3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_4f9a99f5-05b7-4bc9-b172-e72bf1c5c280" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_d3ac741f-9cd1-4e09-adc6-decae5b11dd3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_5a076014-0291-4a70-89b0-18664eb69aae" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_d3ac741f-9cd1-4e09-adc6-decae5b11dd3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_5a076014-0291-4a70-89b0-18664eb69aae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_bee76701-2cc3-422e-9fb2-02d9fdb95e09" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_d3ac741f-9cd1-4e09-adc6-decae5b11dd3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_bee76701-2cc3-422e-9fb2-02d9fdb95e09" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_f295ffc9-50e1-4ae3-8e20-4e2882fcd04d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_d3ac741f-9cd1-4e09-adc6-decae5b11dd3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_f295ffc9-50e1-4ae3-8e20-4e2882fcd04d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_436188b7-952f-457d-88bf-0738f7e2e996" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_d3ac741f-9cd1-4e09-adc6-decae5b11dd3" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_436188b7-952f-457d-88bf-0738f7e2e996" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_71ebefdb-d2f6-4a02-aff0-7dd6db2fa33c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_51cb4db2-f853-4340-acc4-5eaf99db2bdb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_4f9a99f5-05b7-4bc9-b172-e72bf1c5c280" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_51cb4db2-f853-4340-acc4-5eaf99db2bdb" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019c2df4-f5e3-7e1c-afc4-b77a2a2fb111" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_51cb4db2-f853-4340-acc4-5eaf99db2bdb" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019c2df4-f5e3-7e1c-afc4-b77a2a2fb111" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019c2df5-d9ff-7693-9bc2-fab1f0581a44" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_51cb4db2-f853-4340-acc4-5eaf99db2bdb" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019c2df5-d9ff-7693-9bc2-fab1f0581a44" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019c2df6-1ad0-7d98-b176-d5faf377ce6d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_51cb4db2-f853-4340-acc4-5eaf99db2bdb" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019c2df6-1ad0-7d98-b176-d5faf377ce6d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019c2df6-6f25-7d5f-bdbd-cbe8e0eee611" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_51cb4db2-f853-4340-acc4-5eaf99db2bdb" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019c2df6-6f25-7d5f-bdbd-cbe8e0eee611" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_aac9a96b-34a5-40ee-8c7c-2e3f7418a91d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/FinancialandOtherIncomeandExpensesNarrativeDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#FinancialandOtherIncomeandExpensesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/FinancialandOtherIncomeandExpensesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_c33f1bfc-49ec-4186-9280-f29af1b049a9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_d103170f-8b57-4c38-9b1d-919082cae682" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c33f1bfc-49ec-4186-9280-f29af1b049a9" xlink:to="loc_us-gaap_DebtInstrumentTable_d103170f-8b57-4c38-9b1d-919082cae682" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_eb6062b9-843a-4925-b91c-191ad99209ff" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_d103170f-8b57-4c38-9b1d-919082cae682" xlink:to="loc_us-gaap_CreditFacilityAxis_eb6062b9-843a-4925-b91c-191ad99209ff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_eb6062b9-843a-4925-b91c-191ad99209ff_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_eb6062b9-843a-4925-b91c-191ad99209ff" xlink:to="loc_us-gaap_CreditFacilityDomain_eb6062b9-843a-4925-b91c-191ad99209ff_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_b1173cb1-3503-48c7-99e1-350c7108f098" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_eb6062b9-843a-4925-b91c-191ad99209ff" xlink:to="loc_us-gaap_CreditFacilityDomain_b1173cb1-3503-48c7-99e1-350c7108f098" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_dcb51dc4-6240-4e31-a14a-ad98c4efd203" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_b1173cb1-3503-48c7-99e1-350c7108f098" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_dcb51dc4-6240-4e31-a14a-ad98c4efd203" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_3f808db2-24b1-4179-8489-c716c1a41b3a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_d103170f-8b57-4c38-9b1d-919082cae682" xlink:to="loc_us-gaap_DebtInstrumentAxis_3f808db2-24b1-4179-8489-c716c1a41b3a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_3f808db2-24b1-4179-8489-c716c1a41b3a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_3f808db2-24b1-4179-8489-c716c1a41b3a" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_3f808db2-24b1-4179-8489-c716c1a41b3a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_6301b951-bf18-48af-93ea-3c0e43142a9d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_3f808db2-24b1-4179-8489-c716c1a41b3a" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_6301b951-bf18-48af-93ea-3c0e43142a9d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_BankSyndicateRCFMember_ef0d3817-fa02-4e4c-b480-286bdad4cf5e" xlink:href="crto-20251231.xsd#crto_BankSyndicateRCFMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_6301b951-bf18-48af-93ea-3c0e43142a9d" xlink:to="loc_crto_BankSyndicateRCFMember_ef0d3817-fa02-4e4c-b480-286bdad4cf5e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_fe9330e0-45fb-446b-a2f1-1d1a223394f3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_d103170f-8b57-4c38-9b1d-919082cae682" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_fe9330e0-45fb-446b-a2f1-1d1a223394f3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_fe9330e0-45fb-446b-a2f1-1d1a223394f3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_fe9330e0-45fb-446b-a2f1-1d1a223394f3" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_fe9330e0-45fb-446b-a2f1-1d1a223394f3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_d41e3414-ef1e-40e1-9a54-f877c5093e1f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_fe9330e0-45fb-446b-a2f1-1d1a223394f3" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_d41e3414-ef1e-40e1-9a54-f877c5093e1f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_8eb64a8c-d11c-4dd9-8066-3f7bc38133f9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_d41e3414-ef1e-40e1-9a54-f877c5093e1f" xlink:to="loc_us-gaap_LineOfCreditMember_8eb64a8c-d11c-4dd9-8066-3f7bc38133f9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_49725b6e-9ddc-418e-a1e8-6b88701ce5f4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c33f1bfc-49ec-4186-9280-f29af1b049a9" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_49725b6e-9ddc-418e-a1e8-6b88701ce5f4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_21d64c9b-10d3-4001-ac3f-12ddb8da7130" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c33f1bfc-49ec-4186-9280-f29af1b049a9" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_21d64c9b-10d3-4001-ac3f-12ddb8da7130" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/IncomeTaxesNarrativeDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#IncomeTaxesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/IncomeTaxesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExaminationLineItems_7ace39fc-70d5-4274-901e-d7752a6934c1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExaminationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExaminationTable_46d397f7-e259-4e8c-bf8f-40fdc582e01d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExaminationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_7ace39fc-70d5-4274-901e-d7752a6934c1" xlink:to="loc_us-gaap_IncomeTaxExaminationTable_46d397f7-e259-4e8c-bf8f-40fdc582e01d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019b93e1-f805-75fa-9c4a-2ace65c4d162" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeTaxExaminationTable_46d397f7-e259-4e8c-bf8f-40fdc582e01d" xlink:to="loc_dei_LegalEntityAxis_019b93e1-f805-75fa-9c4a-2ace65c4d162" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019b93e1-f805-75fa-9c4a-2ace65c4d162_default" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019b93e1-f805-75fa-9c4a-2ace65c4d162" xlink:to="loc_dei_EntityDomain_019b93e1-f805-75fa-9c4a-2ace65c4d162_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019b93e1-f805-76d3-88bd-9ef2479d9c89" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019b93e1-f805-75fa-9c4a-2ace65c4d162" xlink:to="loc_dei_EntityDomain_019b93e1-f805-76d3-88bd-9ef2479d9c89" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoCorporationMember_019b93e1-f805-7db7-bcf2-e16e281f0574" xlink:href="crto-20251231.xsd#crto_CriteoCorporationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019b93e1-f805-76d3-88bd-9ef2479d9c89" xlink:to="loc_crto_CriteoCorporationMember_019b93e1-f805-7db7-bcf2-e16e281f0574" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoBrazilMember_019b93e1-f805-7ff1-b9ab-63620a6c83ff" xlink:href="crto-20251231.xsd#crto_CriteoBrazilMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019b93e1-f805-76d3-88bd-9ef2479d9c89" xlink:to="loc_crto_CriteoBrazilMember_019b93e1-f805-7ff1-b9ab-63620a6c83ff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoLtdMember_019b93e1-f805-78ef-a836-f7352b4bd8f3" xlink:href="crto-20251231.xsd#crto_CriteoLtdMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019b93e1-f805-76d3-88bd-9ef2479d9c89" xlink:to="loc_crto_CriteoLtdMember_019b93e1-f805-78ef-a836-f7352b4bd8f3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoSingaporeMember_019b93e1-f805-782d-9298-fba4a28d6bca" xlink:href="crto-20251231.xsd#crto_CriteoSingaporeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019b93e1-f805-76d3-88bd-9ef2479d9c89" xlink:to="loc_crto_CriteoSingaporeMember_019b93e1-f805-782d-9298-fba4a28d6bca" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoAustraliaPtyLtdMember_019b93e1-f805-720a-bdc5-7431ff3b8cb5" xlink:href="crto-20251231.xsd#crto_CriteoAustraliaPtyLtdMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019b93e1-f805-76d3-88bd-9ef2479d9c89" xlink:to="loc_crto_CriteoAustraliaPtyLtdMember_019b93e1-f805-720a-bdc5-7431ff3b8cb5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CriteoFranceMember_019b93e1-f805-77f2-a6e9-5f8d1d5853cd" xlink:href="crto-20251231.xsd#crto_CriteoFranceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019b93e1-f805-76d3-88bd-9ef2479d9c89" xlink:to="loc_crto_CriteoFranceMember_019b93e1-f805-77f2-a6e9-5f8d1d5853cd" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_019b93e1-f805-748c-b758-1d45371758fa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeTaxExaminationTable_46d397f7-e259-4e8c-bf8f-40fdc582e01d" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_019b93e1-f805-748c-b758-1d45371758fa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_019b93e1-f805-748c-b758-1d45371758fa_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_019b93e1-f805-748c-b758-1d45371758fa" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_019b93e1-f805-748c-b758-1d45371758fa_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_019b93e1-f805-7ae2-a3fe-77e54906e043" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_019b93e1-f805-748c-b758-1d45371758fa" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_019b93e1-f805-7ae2-a3fe-77e54906e043" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCountryMember_019b93e1-f805-7f85-81ea-4092295edbd4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ForeignCountryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_019b93e1-f805-7ae2-a3fe-77e54906e043" xlink:to="loc_us-gaap_ForeignCountryMember_019b93e1-f805-7f85-81ea-4092295edbd4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_GB_019c2dd4-972f-7887-82e8-919669aedd47" xlink:href="https://xbrl.sec.gov/country/2025/country-2025.xsd#country_GB"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ForeignCountryMember_019b93e1-f805-7f85-81ea-4092295edbd4" xlink:to="loc_country_GB_019c2dd4-972f-7887-82e8-919669aedd47" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_019c7b31-3892-752e-8066-a4c71dc64f2a" xlink:href="https://xbrl.sec.gov/country/2025/country-2025.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ForeignCountryMember_019b93e1-f805-7f85-81ea-4092295edbd4" xlink:to="loc_country_US_019c7b31-3892-752e-8066-a4c71dc64f2a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityNameAxis_019b93e1-f805-7745-a566-e720de36904a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeTaxExaminationTable_46d397f7-e259-4e8c-bf8f-40fdc582e01d" xlink:to="loc_us-gaap_IncomeTaxAuthorityNameAxis_019b93e1-f805-7745-a566-e720de36904a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityNameDomain_019b93e1-f805-7745-a566-e720de36904a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityNameAxis_019b93e1-f805-7745-a566-e720de36904a" xlink:to="loc_us-gaap_IncomeTaxAuthorityNameDomain_019b93e1-f805-7745-a566-e720de36904a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityNameDomain_019b93e1-f805-71cc-a5ee-713c81453834" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityNameAxis_019b93e1-f805-7745-a566-e720de36904a" xlink:to="loc_us-gaap_IncomeTaxAuthorityNameDomain_019b93e1-f805-71cc-a5ee-713c81453834" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalRevenueServiceIRSMember_019b93e1-f805-710a-acce-b6cb47144509" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InternalRevenueServiceIRSMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityNameDomain_019b93e1-f805-71cc-a5ee-713c81453834" xlink:to="loc_us-gaap_InternalRevenueServiceIRSMember_019b93e1-f805-710a-acce-b6cb47144509" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HerMajestysRevenueAndCustomsHMRCMember_019b93e1-f805-7d33-853e-527ba8940875" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_HerMajestysRevenueAndCustomsHMRCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityNameDomain_019b93e1-f805-71cc-a5ee-713c81453834" xlink:to="loc_us-gaap_HerMajestysRevenueAndCustomsHMRCMember_019b93e1-f805-7d33-853e-527ba8940875" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StateAdministrationOfTaxationChinaMember_019b93e1-f805-7f3a-99f4-85a168f13093" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StateAdministrationOfTaxationChinaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityNameDomain_019b93e1-f805-71cc-a5ee-713c81453834" xlink:to="loc_us-gaap_StateAdministrationOfTaxationChinaMember_019b93e1-f805-7f3a-99f4-85a168f13093" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxCreditCarryforwardAxis_019b93e1-f805-7429-aa4b-1158f53d893c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TaxCreditCarryforwardAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeTaxExaminationTable_46d397f7-e259-4e8c-bf8f-40fdc582e01d" xlink:to="loc_us-gaap_TaxCreditCarryforwardAxis_019b93e1-f805-7429-aa4b-1158f53d893c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxCreditCarryforwardNameDomain_019b93e1-f805-7429-aa4b-1158f53d893c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TaxCreditCarryforwardNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TaxCreditCarryforwardAxis_019b93e1-f805-7429-aa4b-1158f53d893c" xlink:to="loc_us-gaap_TaxCreditCarryforwardNameDomain_019b93e1-f805-7429-aa4b-1158f53d893c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxCreditCarryforwardNameDomain_019b93e1-f805-7f18-9446-c5113ef0e26a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TaxCreditCarryforwardNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TaxCreditCarryforwardAxis_019b93e1-f805-7429-aa4b-1158f53d893c" xlink:to="loc_us-gaap_TaxCreditCarryforwardNameDomain_019b93e1-f805-7f18-9446-c5113ef0e26a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchMember_019b93e1-f805-7323-90d4-dfae59823bba" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResearchMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxCreditCarryforwardNameDomain_019b93e1-f805-7f18-9446-c5113ef0e26a" xlink:to="loc_us-gaap_ResearchMember_019b93e1-f805-7323-90d4-dfae59823bba" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReasonablyPossibleSignificantChangeInUnrecognizedTaxBenefitsByItemAxis_019c3335-46b8-7632-8285-e848fb7eb2dc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ReasonablyPossibleSignificantChangeInUnrecognizedTaxBenefitsByItemAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeTaxExaminationTable_46d397f7-e259-4e8c-bf8f-40fdc582e01d" xlink:to="loc_us-gaap_ReasonablyPossibleSignificantChangeInUnrecognizedTaxBenefitsByItemAxis_019c3335-46b8-7632-8285-e848fb7eb2dc" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleNatureOfUncertaintyDomain_019c3335-46b8-7632-8285-e848fb7eb2dc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleNatureOfUncertaintyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ReasonablyPossibleSignificantChangeInUnrecognizedTaxBenefitsByItemAxis_019c3335-46b8-7632-8285-e848fb7eb2dc" xlink:to="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleNatureOfUncertaintyDomain_019c3335-46b8-7632-8285-e848fb7eb2dc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleNatureOfUncertaintyDomain_019c3335-46b8-736f-9000-6e647856ada8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleNatureOfUncertaintyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ReasonablyPossibleSignificantChangeInUnrecognizedTaxBenefitsByItemAxis_019c3335-46b8-7632-8285-e848fb7eb2dc" xlink:to="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleNatureOfUncertaintyDomain_019c3335-46b8-736f-9000-6e647856ada8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockCompensationPlanMember_019c3335-656b-78d0-9ea8-6dedf6bfc9a8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockCompensationPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SignificantChangeInUnrecognizedTaxBenefitsIsReasonablyPossibleNatureOfUncertaintyDomain_019c3335-46b8-736f-9000-6e647856ada8" xlink:to="loc_us-gaap_StockCompensationPlanMember_019c3335-656b-78d0-9ea8-6dedf6bfc9a8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_ProvisionForIncomeTaxesRelatedToPillarTwo_bdbec678-ef17-4032-81b1-4d4e77abbc7d" xlink:href="crto-20251231.xsd#crto_ProvisionForIncomeTaxesRelatedToPillarTwo"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_7ace39fc-70d5-4274-901e-d7752a6934c1" xlink:to="loc_crto_ProvisionForIncomeTaxesRelatedToPillarTwo_bdbec678-ef17-4032-81b1-4d4e77abbc7d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsValuationAllowance_5daf50f9-941a-4b86-863a-2c252e0661a0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsValuationAllowance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_7ace39fc-70d5-4274-901e-d7752a6934c1" xlink:to="loc_us-gaap_DeferredTaxAssetsValuationAllowance_5daf50f9-941a-4b86-863a-2c252e0661a0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount_019c7b32-c290-74c9-ad68-a6cda319602a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_7ace39fc-70d5-4274-901e-d7752a6934c1" xlink:to="loc_us-gaap_ValuationAllowanceDeferredTaxAssetChangeInAmount_019c7b32-c290-74c9-ad68-a6cda319602a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration_4f50dccd-a368-4f4a-a439-269a684aaadc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_7ace39fc-70d5-4274-901e-d7752a6934c1" xlink:to="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsSubjectToExpiration_4f50dccd-a368-4f4a-a439-269a684aaadc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsNotSubjectToExpiration_5d8c5162-2400-4365-be8e-65a02d22218b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsNotSubjectToExpiration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_7ace39fc-70d5-4274-901e-d7752a6934c1" xlink:to="loc_us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsNotSubjectToExpiration_5d8c5162-2400-4365-be8e-65a02d22218b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecognizedTaxBenefits_78c46689-9e7e-4c81-8734-2b196877b008" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrecognizedTaxBenefits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExaminationLineItems_7ace39fc-70d5-4274-901e-d7752a6934c1" xlink:to="loc_us-gaap_UnrecognizedTaxBenefits_78c46689-9e7e-4c81-8734-2b196877b008" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/IncomeTaxesReconciliationBetweentheEffectiveandStandardFrenchRateDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#IncomeTaxesReconciliationBetweentheEffectiveandStandardFrenchRateDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/IncomeTaxesReconciliationBetweentheEffectiveandStandardFrenchRateDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationLineItems_019b9389-16c5-77d4-acfc-65bd82f6a4de" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTable_019b9384-d431-78a4-bf87-9d7dff936d09" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateReconciliationLineItems_019b9389-16c5-77d4-acfc-65bd82f6a4de" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTable_019b9384-d431-78a4-bf87-9d7dff936d09" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_019b9395-00cc-7f0f-aca9-53d2e5ad5aea" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTable_019b9384-d431-78a4-bf87-9d7dff936d09" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_019b9395-00cc-7f0f-aca9-53d2e5ad5aea" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_019b9395-00cc-7f0f-aca9-53d2e5ad5aea_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_019b9395-00cc-7f0f-aca9-53d2e5ad5aea" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_019b9395-00cc-7f0f-aca9-53d2e5ad5aea_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_019b9395-00cc-760f-94be-f80f7c4bdabc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_019b9395-00cc-7f0f-aca9-53d2e5ad5aea" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_019b9395-00cc-760f-94be-f80f7c4bdabc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticCountryMember_019c7a8d-601c-72ec-8819-c330e2016946" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DomesticCountryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_019b9395-00cc-760f-94be-f80f7c4bdabc" xlink:to="loc_us-gaap_DomesticCountryMember_019c7a8d-601c-72ec-8819-c330e2016946" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_FR_019c7a89-aca3-71f7-a0d1-4c49c7512a3d" xlink:href="https://xbrl.sec.gov/country/2025/country-2025.xsd#country_FR"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticCountryMember_019c7a8d-601c-72ec-8819-c330e2016946" xlink:to="loc_country_FR_019c7a89-aca3-71f7-a0d1-4c49c7512a3d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCountryMember_019c7a8d-a09a-7e20-86d9-2d395216b510" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ForeignCountryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_019b9395-00cc-760f-94be-f80f7c4bdabc" xlink:to="loc_us-gaap_ForeignCountryMember_019c7a8d-a09a-7e20-86d9-2d395216b510" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_019b9395-a68d-7f2b-96e1-4c30e8d2997a" xlink:href="https://xbrl.sec.gov/country/2025/country-2025.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ForeignCountryMember_019c7a8d-a09a-7e20-86d9-2d395216b510" xlink:to="loc_country_US_019b9395-a68d-7f2b-96e1-4c30e8d2997a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_DE_019b9397-7426-7bb8-ade4-f4dabde21fb5" xlink:href="https://xbrl.sec.gov/country/2025/country-2025.xsd#country_DE"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ForeignCountryMember_019c7a8d-a09a-7e20-86d9-2d395216b510" xlink:to="loc_country_DE_019b9397-7426-7bb8-ade4-f4dabde21fb5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_GB_019b9397-d646-71f3-8701-5e1adc6a5ed3" xlink:href="https://xbrl.sec.gov/country/2025/country-2025.xsd#country_GB"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ForeignCountryMember_019c7a8d-a09a-7e20-86d9-2d395216b510" xlink:to="loc_country_GB_019b9397-d646-71f3-8701-5e1adc6a5ed3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignTaxJurisdictionOtherMember_019b9396-852c-7c5f-90c5-ceb1a4914987" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ForeignTaxJurisdictionOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ForeignCountryMember_019c7a8d-a09a-7e20-86d9-2d395216b510" xlink:to="loc_us-gaap_ForeignTaxJurisdictionOtherMember_019b9396-852c-7c5f-90c5-ceb1a4914987" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract_26ad8556-0410-40d2-a81b-4cc2d6550cfe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateReconciliationLineItems_019b9389-16c5-77d4-acfc-65bd82f6a4de" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract_26ad8556-0410-40d2-a81b-4cc2d6550cfe" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate_019c2dc1-4dcc-72bd-a456-6bfbbe5f1c89" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract_26ad8556-0410-40d2-a81b-4cc2d6550cfe" xlink:to="loc_us-gaap_IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate_019c2dc1-4dcc-72bd-a456-6bfbbe5f1c89" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReconciliationNondeductibleExpense_019c2dc2-8929-7545-8929-5f78b9f28d75" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationNondeductibleExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract_26ad8556-0410-40d2-a81b-4cc2d6550cfe" xlink:to="loc_us-gaap_IncomeTaxReconciliationNondeductibleExpense_019c2dc2-8929-7545-8929-5f78b9f28d75" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_EffectiveIncomeTaxRateReconciliationIncomeEligibleToReducedTaxationRate_019c7b56-1de7-7d6f-85d5-8768ce2f1ad9" xlink:href="crto-20251231.xsd#crto_EffectiveIncomeTaxRateReconciliationIncomeEligibleToReducedTaxationRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract_26ad8556-0410-40d2-a81b-4cc2d6550cfe" xlink:to="loc_crto_EffectiveIncomeTaxRateReconciliationIncomeEligibleToReducedTaxationRate_019c7b56-1de7-7d6f-85d5-8768ce2f1ad9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReconciliationTaxContingencies_019c2dc2-8929-71a3-8e46-197946f00df7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationTaxContingencies"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract_26ad8556-0410-40d2-a81b-4cc2d6550cfe" xlink:to="loc_us-gaap_IncomeTaxReconciliationTaxContingencies_019c2dc2-8929-71a3-8e46-197946f00df7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReconciliationOtherAdjustments_019c2dc2-8929-705b-ba66-248096165579" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationOtherAdjustments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract_26ad8556-0410-40d2-a81b-4cc2d6550cfe" xlink:to="loc_us-gaap_IncomeTaxReconciliationOtherAdjustments_019c2dc2-8929-705b-ba66-248096165579" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential_019c2dc2-8929-79b3-bd20-b76b9f3b8825" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract_26ad8556-0410-40d2-a81b-4cc2d6550cfe" xlink:to="loc_us-gaap_IncomeTaxReconciliationForeignIncomeTaxRateDifferential_019c2dc2-8929-79b3-bd20-b76b9f3b8825" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes_019c2dc2-8929-7315-88c2-7d7e552b3880" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract_26ad8556-0410-40d2-a81b-4cc2d6550cfe" xlink:to="loc_us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes_019c2dc2-8929-7315-88c2-7d7e552b3880" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance_019c2dc2-8929-77bc-b431-95f7db67c791" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract_26ad8556-0410-40d2-a81b-4cc2d6550cfe" xlink:to="loc_us-gaap_IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance_019c2dc2-8929-77bc-b431-95f7db67c791" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_019c2dc2-8929-72fc-8767-adb3d0231fb1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxExpenseBenefitContinuingOperationsIncomeTaxReconciliationAbstract_26ad8556-0410-40d2-a81b-4cc2d6550cfe" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_019c2dc2-8929-72fc-8767-adb3d0231fb1" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract_019b9389-9a00-778a-82d7-dd4808703818" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateReconciliationLineItems_019b9389-16c5-77d4-acfc-65bd82f6a4de" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract_019b9389-9a00-778a-82d7-dd4808703818" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_019c2dec-6ba6-7604-a20f-f6d052742f30" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract_019b9389-9a00-778a-82d7-dd4808703818" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_019c2dec-6ba6-7604-a20f-f6d052742f30" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpense_019c2dc5-5b6d-7fd6-b1c7-acca06964c3e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract_019b9389-9a00-778a-82d7-dd4808703818" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpense_019c2dc5-5b6d-7fd6-b1c7-acca06964c3e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_EffectiveIncomeTaxRateReconciliationIncomeEligibleToReducedTaxationRatePercent_019c7b57-3c88-74cd-913c-8275d6753bf6" xlink:href="crto-20251231.xsd#crto_EffectiveIncomeTaxRateReconciliationIncomeEligibleToReducedTaxationRatePercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract_019b9389-9a00-778a-82d7-dd4808703818" xlink:to="loc_crto_EffectiveIncomeTaxRateReconciliationIncomeEligibleToReducedTaxationRatePercent_019c7b57-3c88-74cd-913c-8275d6753bf6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTaxContingencies_019c2dc5-5b6d-7681-ae1b-d17f754231f1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationTaxContingencies"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract_019b9389-9a00-778a-82d7-dd4808703818" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationTaxContingencies_019c2dc5-5b6d-7681-ae1b-d17f754231f1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments_019c2dc5-5b6d-7e9a-88d4-d84088cb31ee" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract_019b9389-9a00-778a-82d7-dd4808703818" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments_019c2dc5-5b6d-7e9a-88d4-d84088cb31ee" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential_019c2dc5-5b6d-75d4-939e-a14a3643ffdc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract_019b9389-9a00-778a-82d7-dd4808703818" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential_019c2dc5-5b6d-75d4-939e-a14a3643ffdc" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_019c2dc5-5b6d-7a57-b69c-d7a667972a52" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract_019b9389-9a00-778a-82d7-dd4808703818" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_019c2dc5-5b6d-7a57-b69c-d7a667972a52" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance_019c2dc5-5b6d-783f-84d9-f34680d7c950" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract_019b9389-9a00-778a-82d7-dd4808703818" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance_019c2dc5-5b6d-783f-84d9-f34680d7c950" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_019c2dc5-5b6d-7469-88c3-0fe2fe8a5e75" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract_019b9389-9a00-778a-82d7-dd4808703818" xlink:to="loc_us-gaap_EffectiveIncomeTaxRateContinuingOperations_019c2dc5-5b6d-7469-88c3-0fe2fe8a5e75" xlink:type="arc" order="9"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/IncomeTaxesSummaryofCashPaidforIncomeTaxesDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#IncomeTaxesSummaryofCashPaidforIncomeTaxesDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/IncomeTaxesSummaryofCashPaidforIncomeTaxesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems_019c2dd8-bbd8-79d8-915e-6b5a30ef9588" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxPaidByIndividualJurisdictionTable_019c2dd8-2eb9-7e22-bdac-715225b8f16a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPaidByIndividualJurisdictionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems_019c2dd8-bbd8-79d8-915e-6b5a30ef9588" xlink:to="loc_us-gaap_IncomeTaxPaidByIndividualJurisdictionTable_019c2dd8-2eb9-7e22-bdac-715225b8f16a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_019c2dd8-bbd8-7ade-962f-6868d259b14c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeTaxPaidByIndividualJurisdictionTable_019c2dd8-2eb9-7e22-bdac-715225b8f16a" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_019c2dd8-bbd8-7ade-962f-6868d259b14c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_019c2dd8-bbd8-7ade-962f-6868d259b14c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_019c2dd8-bbd8-7ade-962f-6868d259b14c" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_019c2dd8-bbd8-7ade-962f-6868d259b14c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_019c2dd8-bbd8-721c-890d-e8480c086a80" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_019c2dd8-bbd8-7ade-962f-6868d259b14c" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_019c2dd8-bbd8-721c-890d-e8480c086a80" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCountryMember_019c7b34-bd67-7a1c-a131-91d8c046382d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ForeignCountryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_019c2dd8-bbd8-721c-890d-e8480c086a80" xlink:to="loc_us-gaap_ForeignCountryMember_019c7b34-bd67-7a1c-a131-91d8c046382d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_019c2dd8-bbd8-7d6a-85c2-e636243de6b1" xlink:href="https://xbrl.sec.gov/country/2025/country-2025.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ForeignCountryMember_019c7b34-bd67-7a1c-a131-91d8c046382d" xlink:to="loc_country_US_019c2dd8-bbd8-7d6a-85c2-e636243de6b1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_JP_019c2dd8-bbd8-72ee-8037-6e255ace0028" xlink:href="https://xbrl.sec.gov/country/2025/country-2025.xsd#country_JP"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ForeignCountryMember_019c7b34-bd67-7a1c-a131-91d8c046382d" xlink:to="loc_country_JP_019c2dd8-bbd8-72ee-8037-6e255ace0028" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_ES_019c2dd8-bbd8-7774-b5b7-181ba8884748" xlink:href="https://xbrl.sec.gov/country/2025/country-2025.xsd#country_ES"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ForeignCountryMember_019c7b34-bd67-7a1c-a131-91d8c046382d" xlink:to="loc_country_ES_019c2dd8-bbd8-7774-b5b7-181ba8884748" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignTaxJurisdictionOtherMember_019c2dd9-251e-7603-82ae-861f55720bd8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ForeignTaxJurisdictionOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ForeignCountryMember_019c7b34-bd67-7a1c-a131-91d8c046382d" xlink:to="loc_us-gaap_ForeignTaxJurisdictionOtherMember_019c2dd9-251e-7603-82ae-861f55720bd8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxPaidFederalAfterRefundReceived_019c2dda-20d4-722f-829e-282b5dc8d5b1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPaidFederalAfterRefundReceived"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems_019c2dd8-bbd8-79d8-915e-6b5a30ef9588" xlink:to="loc_us-gaap_IncomeTaxPaidFederalAfterRefundReceived_019c2dda-20d4-722f-829e-282b5dc8d5b1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxPaidForeignAfterRefundReceivedAbstract_019c2dda-8606-77f9-aa55-b54d3c88941e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPaidForeignAfterRefundReceivedAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems_019c2dd8-bbd8-79d8-915e-6b5a30ef9588" xlink:to="loc_us-gaap_IncomeTaxPaidForeignAfterRefundReceivedAbstract_019c2dda-8606-77f9-aa55-b54d3c88941e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxPaidForeignAfterRefundReceived_019c2dd8-bbd8-7783-9bac-408c3701041c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxPaidForeignAfterRefundReceived"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxPaidForeignAfterRefundReceivedAbstract_019c2dda-8606-77f9-aa55-b54d3c88941e" xlink:to="loc_us-gaap_IncomeTaxPaidForeignAfterRefundReceived_019c2dd8-bbd8-7783-9bac-408c3701041c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxesPaidNet_019c2ddd-d3b8-7b9d-95c4-4ef75afadc13" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeTaxesPaidNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxPaidByIndividualJurisdictionLineItems_019c2dd8-bbd8-79d8-915e-6b5a30ef9588" xlink:to="loc_us-gaap_IncomeTaxesPaidNet_019c2ddd-d3b8-7b9d-95c4-4ef75afadc13" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/EarningsPerShareAntiDilutiveSecuritiesDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#EarningsPerShareAntiDilutiveSecuritiesDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/EarningsPerShareAntiDilutiveSecuritiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_4bfaf3b4-25db-4f46-a0fe-4ddafbf31fd8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_7c8e3eca-f9c6-41d9-a09c-7868c88d6761" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_4bfaf3b4-25db-4f46-a0fe-4ddafbf31fd8" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_7c8e3eca-f9c6-41d9-a09c-7868c88d6761" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_86805f73-45a7-4a27-8f24-d289f8d59134" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_7c8e3eca-f9c6-41d9-a09c-7868c88d6761" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_86805f73-45a7-4a27-8f24-d289f8d59134" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_86805f73-45a7-4a27-8f24-d289f8d59134_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_86805f73-45a7-4a27-8f24-d289f8d59134" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_86805f73-45a7-4a27-8f24-d289f8d59134_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_41f7fb9c-a133-453c-9bd6-e9ab190a5cc0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_86805f73-45a7-4a27-8f24-d289f8d59134" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_41f7fb9c-a133-453c-9bd6-e9ab190a5cc0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_187c06d4-c1a3-4d88-b84d-43c9c57c2523" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_41f7fb9c-a133-453c-9bd6-e9ab190a5cc0" xlink:to="loc_us-gaap_RestrictedStockMember_187c06d4-c1a3-4d88-b84d-43c9c57c2523" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_d7e0dd7f-f4f1-4160-9895-341a786acd1f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_4bfaf3b4-25db-4f46-a0fe-4ddafbf31fd8" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_d7e0dd7f-f4f1-4160-9895-341a786acd1f" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/CommitmentsandcontingenciesNarrativeDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#CommitmentsandcontingenciesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/CommitmentsandcontingenciesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesLineItems_cf3cf76c-c4b2-44d3-92a5-cfd6472e7a08" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossContingenciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesTable_16a42c57-93b2-422c-8ed9-ac7146fd60af" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossContingenciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_cf3cf76c-c4b2-44d3-92a5-cfd6472e7a08" xlink:to="loc_us-gaap_LossContingenciesTable_16a42c57-93b2-422c-8ed9-ac7146fd60af" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_f50c814c-d8c2-4ef7-adbd-e2f4eb785309" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_16a42c57-93b2-422c-8ed9-ac7146fd60af" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_f50c814c-d8c2-4ef7-adbd-e2f4eb785309" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_f50c814c-d8c2-4ef7-adbd-e2f4eb785309_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_f50c814c-d8c2-4ef7-adbd-e2f4eb785309" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_f50c814c-d8c2-4ef7-adbd-e2f4eb785309_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_8b4516a6-4e8f-46aa-bd99-615165203941" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_f50c814c-d8c2-4ef7-adbd-e2f4eb785309" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_8b4516a6-4e8f-46aa-bd99-615165203941" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_SoftwareLicensesMaintenanceAndBandwidthForServersMember_ee48d041-a609-4806-b3d3-45350d7cbd6b" xlink:href="crto-20251231.xsd#crto_SoftwareLicensesMaintenanceAndBandwidthForServersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_8b4516a6-4e8f-46aa-bd99-615165203941" xlink:to="loc_crto_SoftwareLicensesMaintenanceAndBandwidthForServersMember_ee48d041-a609-4806-b3d3-45350d7cbd6b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseAxis_ae22661b-c598-4b6c-8c6b-b4a3c03c2566" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_LitigationCaseAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_16a42c57-93b2-422c-8ed9-ac7146fd60af" xlink:to="loc_srt_LitigationCaseAxis_ae22661b-c598-4b6c-8c6b-b4a3c03c2566" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseTypeDomain_ae22661b-c598-4b6c-8c6b-b4a3c03c2566_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_LitigationCaseTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_LitigationCaseAxis_ae22661b-c598-4b6c-8c6b-b4a3c03c2566" xlink:to="loc_srt_LitigationCaseTypeDomain_ae22661b-c598-4b6c-8c6b-b4a3c03c2566_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseTypeDomain_727fc3d7-c629-4180-9fad-65ce565a4357" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_LitigationCaseTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_LitigationCaseAxis_ae22661b-c598-4b6c-8c6b-b4a3c03c2566" xlink:to="loc_srt_LitigationCaseTypeDomain_727fc3d7-c629-4180-9fad-65ce565a4357" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CommissionNationaleDeLInformatiqueEtDesLibertesCNILMember_019b93e9-45a8-7d21-882c-71a8a6db5045" xlink:href="crto-20251231.xsd#crto_CommissionNationaleDeLInformatiqueEtDesLibertesCNILMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_727fc3d7-c629-4180-9fad-65ce565a4357" xlink:to="loc_crto_CommissionNationaleDeLInformatiqueEtDesLibertesCNILMember_019b93e9-45a8-7d21-882c-71a8a6db5045" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_DoeVs.GoodRxHoldingsInc.Member_a9e1d64f-fe54-42c6-8409-c6098232c670" xlink:href="crto-20251231.xsd#crto_DoeVs.GoodRxHoldingsInc.Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_727fc3d7-c629-4180-9fad-65ce565a4357" xlink:to="loc_crto_DoeVs.GoodRxHoldingsInc.Member_a9e1d64f-fe54-42c6-8409-c6098232c670" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_a3de38d0-8611-449a-86eb-241a1ce6e7de" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_16a42c57-93b2-422c-8ed9-ac7146fd60af" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_a3de38d0-8611-449a-86eb-241a1ce6e7de" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_a3de38d0-8611-449a-86eb-241a1ce6e7de_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_a3de38d0-8611-449a-86eb-241a1ce6e7de" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_a3de38d0-8611-449a-86eb-241a1ce6e7de_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_144b78e5-32cf-40d1-ae64-56de295e49a0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_a3de38d0-8611-449a-86eb-241a1ce6e7de" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_144b78e5-32cf-40d1-ae64-56de295e49a0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_IponwebMember_200e36b8-ebbe-47d1-ab2d-437ba9089d5b" xlink:href="crto-20251231.xsd#crto_IponwebMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_144b78e5-32cf-40d1-ae64-56de295e49a0" xlink:to="loc_crto_IponwebMember_200e36b8-ebbe-47d1-ab2d-437ba9089d5b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractualObligation_150eca93-9ea7-41d4-857b-0cf6b42cc9be" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractualObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_cf3cf76c-c4b2-44d3-92a5-cfd6472e7a08" xlink:to="loc_us-gaap_ContractualObligation_150eca93-9ea7-41d4-857b-0cf6b42cc9be" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyEstimateOfPossibleLoss_6755af0a-2730-49fe-8043-566ae36efc3e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossContingencyEstimateOfPossibleLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_cf3cf76c-c4b2-44d3-92a5-cfd6472e7a08" xlink:to="loc_us-gaap_LossContingencyEstimateOfPossibleLoss_6755af0a-2730-49fe-8043-566ae36efc3e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyAccrualAtCarryingValue_72644c12-32ad-4c77-9125-dfcf89e86e6b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossContingencyAccrualAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_cf3cf76c-c4b2-44d3-92a5-cfd6472e7a08" xlink:to="loc_us-gaap_LossContingencyAccrualAtCarryingValue_72644c12-32ad-4c77-9125-dfcf89e86e6b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyReceivable_0c1475d6-4ea8-48fc-ae30-e0220a9ba13a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossContingencyReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_cf3cf76c-c4b2-44d3-92a5-cfd6472e7a08" xlink:to="loc_us-gaap_LossContingencyReceivable_0c1475d6-4ea8-48fc-ae30-e0220a9ba13a" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/CommitmentsandcontingenciesContractualCommitmentsDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#CommitmentsandcontingenciesContractualCommitmentsDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/CommitmentsandcontingenciesContractualCommitmentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_e8fd3a52-0c25-4aa9-a5a2-570bfd04ad96" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_c1fac1d1-dfcd-4dec-8227-9c475c144892" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e8fd3a52-0c25-4aa9-a5a2-570bfd04ad96" xlink:to="loc_us-gaap_DebtInstrumentTable_c1fac1d1-dfcd-4dec-8227-9c475c144892" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_b518322a-7cd3-41f2-8308-b0b10d878489" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_c1fac1d1-dfcd-4dec-8227-9c475c144892" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_b518322a-7cd3-41f2-8308-b0b10d878489" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_b518322a-7cd3-41f2-8308-b0b10d878489_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_b518322a-7cd3-41f2-8308-b0b10d878489" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_b518322a-7cd3-41f2-8308-b0b10d878489_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_07d4dc28-5384-4ff7-a61a-0bb37e21b4ea" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_b518322a-7cd3-41f2-8308-b0b10d878489" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_07d4dc28-5384-4ff7-a61a-0bb37e21b4ea" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_SoftwareLicensesMaintenanceAndBandwidthForServersMember_ac308a49-dbab-401d-8506-dd2f4db1d3f9" xlink:href="crto-20251231.xsd#crto_SoftwareLicensesMaintenanceAndBandwidthForServersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_07d4dc28-5384-4ff7-a61a-0bb37e21b4ea" xlink:to="loc_crto_SoftwareLicensesMaintenanceAndBandwidthForServersMember_ac308a49-dbab-401d-8506-dd2f4db1d3f9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractualObligationDueInNextTwelveMonths_8ac831de-4ea9-4021-a344-1771bd53172d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractualObligationDueInNextTwelveMonths"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e8fd3a52-0c25-4aa9-a5a2-570bfd04ad96" xlink:to="loc_us-gaap_ContractualObligationDueInNextTwelveMonths_8ac831de-4ea9-4021-a344-1771bd53172d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractualObligationDueInSecondYear_e5c3386a-3ba7-4659-ab5e-1e566068ba5c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractualObligationDueInSecondYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e8fd3a52-0c25-4aa9-a5a2-570bfd04ad96" xlink:to="loc_us-gaap_ContractualObligationDueInSecondYear_e5c3386a-3ba7-4659-ab5e-1e566068ba5c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractualObligationDueInThirdYear_1b41b50a-c20e-4a72-9494-41498dcff633" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractualObligationDueInThirdYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e8fd3a52-0c25-4aa9-a5a2-570bfd04ad96" xlink:to="loc_us-gaap_ContractualObligationDueInThirdYear_1b41b50a-c20e-4a72-9494-41498dcff633" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractualObligationDueInFourthYear_019c2e67-4974-72c1-ab47-19b1ef643fc0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractualObligationDueInFourthYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e8fd3a52-0c25-4aa9-a5a2-570bfd04ad96" xlink:to="loc_us-gaap_ContractualObligationDueInFourthYear_019c2e67-4974-72c1-ab47-19b1ef643fc0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractualObligationDueInFifthYear_019c2e67-8dd6-791b-957d-ade25e2d15a3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractualObligationDueInFifthYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e8fd3a52-0c25-4aa9-a5a2-570bfd04ad96" xlink:to="loc_us-gaap_ContractualObligationDueInFifthYear_019c2e67-8dd6-791b-957d-ade25e2d15a3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractualObligation_ef9582e7-df68-41cd-ad23-de3ef4300675" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractualObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e8fd3a52-0c25-4aa9-a5a2-570bfd04ad96" xlink:to="loc_us-gaap_ContractualObligation_ef9582e7-df68-41cd-ad23-de3ef4300675" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/BreakdownofRevenueandNoncurrentAssetsScheduleofRevenuebyProductandServicesDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#BreakdownofRevenueandNoncurrentAssetsScheduleofRevenuebyProductandServicesDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/BreakdownofRevenueandNoncurrentAssetsScheduleofRevenuebyProductandServicesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_2ed40437-eb8d-465c-af3b-ba5c9dba1656" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_14405259-b7ea-4408-9b1f-1ab5c6d39254" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_2ed40437-eb8d-465c-af3b-ba5c9dba1656" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_14405259-b7ea-4408-9b1f-1ab5c6d39254" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_b85de0f3-2456-4814-837e-5fa7148062a2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_14405259-b7ea-4408-9b1f-1ab5c6d39254" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_b85de0f3-2456-4814-837e-5fa7148062a2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_b85de0f3-2456-4814-837e-5fa7148062a2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_b85de0f3-2456-4814-837e-5fa7148062a2" xlink:to="loc_us-gaap_SegmentDomain_b85de0f3-2456-4814-837e-5fa7148062a2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_3f97d577-4bbd-4cb8-ac60-b8124637d650" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_b85de0f3-2456-4814-837e-5fa7148062a2" xlink:to="loc_us-gaap_SegmentDomain_3f97d577-4bbd-4cb8-ac60-b8124637d650" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_RetailMediaMember_185af1cd-b73e-40f0-af2e-27310cdb5c4f" xlink:href="crto-20251231.xsd#crto_RetailMediaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_3f97d577-4bbd-4cb8-ac60-b8124637d650" xlink:to="loc_crto_RetailMediaMember_185af1cd-b73e-40f0-af2e-27310cdb5c4f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_PerformanceMediaMember_f75374ec-5b34-4cc4-b6d2-0069368571b5" xlink:href="crto-20251231.xsd#crto_PerformanceMediaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_3f97d577-4bbd-4cb8-ac60-b8124637d650" xlink:to="loc_crto_PerformanceMediaMember_f75374ec-5b34-4cc4-b6d2-0069368571b5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_d6e66c96-ac37-4fb9-9081-3eaef064dd52" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_14405259-b7ea-4408-9b1f-1ab5c6d39254" xlink:to="loc_srt_ProductOrServiceAxis_d6e66c96-ac37-4fb9-9081-3eaef064dd52" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_d6e66c96-ac37-4fb9-9081-3eaef064dd52_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_d6e66c96-ac37-4fb9-9081-3eaef064dd52" xlink:to="loc_srt_ProductsAndServicesDomain_d6e66c96-ac37-4fb9-9081-3eaef064dd52_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_33bc5742-9a97-476f-9157-d015823e4d7e" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_d6e66c96-ac37-4fb9-9081-3eaef064dd52" xlink:to="loc_srt_ProductsAndServicesDomain_33bc5742-9a97-476f-9157-d015823e4d7e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_CommerceGrowthMember_2571e267-46dd-4c85-bfd6-9cef5374f017" xlink:href="crto-20251231.xsd#crto_CommerceGrowthMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_33bc5742-9a97-476f-9157-d015823e4d7e" xlink:to="loc_crto_CommerceGrowthMember_2571e267-46dd-4c85-bfd6-9cef5374f017" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_crto_OtherMember_546aa884-2ce6-4371-a606-ddb898572c78" xlink:href="crto-20251231.xsd#crto_OtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_33bc5742-9a97-476f-9157-d015823e4d7e" xlink:to="loc_crto_OtherMember_546aa884-2ce6-4371-a606-ddb898572c78" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_8ff5fbab-c9c5-45d5-82a0-6f0bfce4cc0e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_2ed40437-eb8d-465c-af3b-ba5c9dba1656" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_8ff5fbab-c9c5-45d5-82a0-6f0bfce4cc0e" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/BreakdownofRevenueandNoncurrentAssetsScheduleofRevenuebyGeographicAreaDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#BreakdownofRevenueandNoncurrentAssetsScheduleofRevenuebyGeographicAreaDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/BreakdownofRevenueandNoncurrentAssetsScheduleofRevenuebyGeographicAreaDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_0fc7adeb-60ad-4f42-a20a-24449600e243" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_1a48104c-e2a4-45c5-b9eb-c5efb9ec3b0d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_0fc7adeb-60ad-4f42-a20a-24449600e243" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_1a48104c-e2a4-45c5-b9eb-c5efb9ec3b0d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_234431d6-1d18-4888-a5a4-bf3388f16360" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_1a48104c-e2a4-45c5-b9eb-c5efb9ec3b0d" xlink:to="loc_srt_StatementGeographicalAxis_234431d6-1d18-4888-a5a4-bf3388f16360" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_234431d6-1d18-4888-a5a4-bf3388f16360_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_234431d6-1d18-4888-a5a4-bf3388f16360" xlink:to="loc_srt_SegmentGeographicalDomain_234431d6-1d18-4888-a5a4-bf3388f16360_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_5056ca7c-7a7f-4284-8a7b-48e7dc157c3d" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_234431d6-1d18-4888-a5a4-bf3388f16360" xlink:to="loc_srt_SegmentGeographicalDomain_5056ca7c-7a7f-4284-8a7b-48e7dc157c3d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AmericasMember_e4645c32-842c-4110-82ce-211e3cef792b" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_AmericasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_5056ca7c-7a7f-4284-8a7b-48e7dc157c3d" xlink:to="loc_srt_AmericasMember_e4645c32-842c-4110-82ce-211e3cef792b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_a611324e-db27-41a5-9c7e-9f952c554e65" xlink:href="https://xbrl.sec.gov/country/2025/country-2025.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_AmericasMember_e4645c32-842c-4110-82ce-211e3cef792b" xlink:to="loc_country_US_a611324e-db27-41a5-9c7e-9f952c554e65" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EMEAMember_50391548-bd88-4c3a-a8b3-24d8e2966d08" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EMEAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_5056ca7c-7a7f-4284-8a7b-48e7dc157c3d" xlink:to="loc_us-gaap_EMEAMember_50391548-bd88-4c3a-a8b3-24d8e2966d08" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_DE_d2bc767f-8d1b-4c5d-a72a-bcebc1157e47" xlink:href="https://xbrl.sec.gov/country/2025/country-2025.xsd#country_DE"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EMEAMember_50391548-bd88-4c3a-a8b3-24d8e2966d08" xlink:to="loc_country_DE_d2bc767f-8d1b-4c5d-a72a-bcebc1157e47" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_FR_53b00a55-c064-432c-98f0-a8736e0c54ec" xlink:href="https://xbrl.sec.gov/country/2025/country-2025.xsd#country_FR"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EMEAMember_50391548-bd88-4c3a-a8b3-24d8e2966d08" xlink:to="loc_country_FR_53b00a55-c064-432c-98f0-a8736e0c54ec" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AsiaPacificMember_ab77fc2c-ee5e-49a9-a080-b95562469c88" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_AsiaPacificMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_5056ca7c-7a7f-4284-8a7b-48e7dc157c3d" xlink:to="loc_srt_AsiaPacificMember_ab77fc2c-ee5e-49a9-a080-b95562469c88" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_JP_bdcfa762-1da4-4b33-9f0e-a1feb852079d" xlink:href="https://xbrl.sec.gov/country/2025/country-2025.xsd#country_JP"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_AsiaPacificMember_ab77fc2c-ee5e-49a9-a080-b95562469c88" xlink:to="loc_country_JP_bdcfa762-1da4-4b33-9f0e-a1feb852079d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_193a3691-1461-45a1-9863-986b8b8e78f6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_0fc7adeb-60ad-4f42-a20a-24449600e243" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_193a3691-1461-45a1-9863-986b8b8e78f6" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/BreakdownofRevenueandNoncurrentAssetsScheduleofLongLivedAssetsbyGeographicalAreaDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#BreakdownofRevenueandNoncurrentAssetsScheduleofLongLivedAssetsbyGeographicalAreaDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/BreakdownofRevenueandNoncurrentAssetsScheduleofLongLivedAssetsbyGeographicalAreaDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_2b9263e2-02f8-46b6-a27b-f8ba7f037072" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_95ba0a6f-8282-419d-9ac3-e756f7f34741" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_2b9263e2-02f8-46b6-a27b-f8ba7f037072" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_95ba0a6f-8282-419d-9ac3-e756f7f34741" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_9249ac21-3300-4c32-8580-14d3ae9da266" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_95ba0a6f-8282-419d-9ac3-e756f7f34741" xlink:to="loc_srt_StatementGeographicalAxis_9249ac21-3300-4c32-8580-14d3ae9da266" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_9249ac21-3300-4c32-8580-14d3ae9da266_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_9249ac21-3300-4c32-8580-14d3ae9da266" xlink:to="loc_srt_SegmentGeographicalDomain_9249ac21-3300-4c32-8580-14d3ae9da266_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_6ec4ac46-9f63-4735-b7d1-ec5db036a85c" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_9249ac21-3300-4c32-8580-14d3ae9da266" xlink:to="loc_srt_SegmentGeographicalDomain_6ec4ac46-9f63-4735-b7d1-ec5db036a85c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AmericasMember_db87d984-6af5-49ee-aae5-b9090608117a" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_AmericasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_6ec4ac46-9f63-4735-b7d1-ec5db036a85c" xlink:to="loc_srt_AmericasMember_db87d984-6af5-49ee-aae5-b9090608117a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EMEAMember_97201b5a-5ba7-4762-b845-145aea5c519b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EMEAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_6ec4ac46-9f63-4735-b7d1-ec5db036a85c" xlink:to="loc_us-gaap_EMEAMember_97201b5a-5ba7-4762-b845-145aea5c519b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AsiaPacificMember_1c1c3230-7cc9-4767-8475-e3bfa3b05a52" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_AsiaPacificMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_6ec4ac46-9f63-4735-b7d1-ec5db036a85c" xlink:to="loc_srt_AsiaPacificMember_1c1c3230-7cc9-4767-8475-e3bfa3b05a52" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncurrentAssets_3bac574a-7d45-4605-85fd-1d9889cff8c2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoncurrentAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_2b9263e2-02f8-46b6-a27b-f8ba7f037072" xlink:to="loc_us-gaap_NoncurrentAssets_3bac574a-7d45-4605-85fd-1d9889cff8c2" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.criteo.com/role/SubsequentEventsDetails" xlink:type="simple" xlink:href="crto-20251231.xsd#SubsequentEventsDetails"/>
  <link:definitionLink xlink:role="http://www.criteo.com/role/SubsequentEventsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventLineItems_019c751f-edd6-7d2d-b58b-fe64dbb65e38" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTable_019c751f-ad26-74cc-895c-402bfd2569d4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems_019c751f-edd6-7d2d-b58b-fe64dbb65e38" xlink:to="loc_us-gaap_SubsequentEventTable_019c751f-ad26-74cc-895c-402bfd2569d4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_019c751f-edd6-783c-b901-61ccf4b0c69b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_019c751f-ad26-74cc-895c-402bfd2569d4" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_019c751f-edd6-783c-b901-61ccf4b0c69b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019c751f-edd6-783c-b901-61ccf4b0c69b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019c751f-edd6-783c-b901-61ccf4b0c69b" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019c751f-edd6-783c-b901-61ccf4b0c69b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019c751f-edd6-7545-ba30-8f4c588a2820" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_019c751f-edd6-783c-b901-61ccf4b0c69b" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019c751f-edd6-7545-ba30-8f4c588a2820" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_019c7520-a8c6-732c-9f61-b874f47231a9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_019c751f-edd6-7545-ba30-8f4c588a2820" xlink:to="loc_us-gaap_SubsequentEventMember_019c7520-a8c6-732c-9f61-b874f47231a9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_019c9412-1e42-70ab-b8ab-106a85e4c7b9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019c751f-edd6-7d2d-b58b-fe64dbb65e38" xlink:to="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_019c9412-1e42-70ab-b8ab-106a85e4c7b9" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists" xlink:type="simple" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-roles-2025.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_IncomeStatementAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementAbstract"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ResearchAndDevelopmentExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementAbstract" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense" xlink:type="arc" order="691"/>
  </link:definitionLink>
</link:linkbase>
