<?xml version="1.0" encoding="us-ascii"?>
<!-- Created by Merrill Corporation -->
<!-- Generated by Fujitsu Interstage XWand B0189 -->
<!--Generated by IRIS XBRL Generation Engine-->
<link:linkbase xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:xlink="http://www.w3.org/1999/xlink">
  <link:roleRef roleURI="http://www.2u.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails3" xlink:type="simple" xlink:href="twou-20140630.xsd#DisclosureSummaryOfSignificantAccountingPoliciesDetails3" />
  <link:roleRef roleURI="http://www.2u.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails4" xlink:type="simple" xlink:href="twou-20140630.xsd#DisclosureSummaryOfSignificantAccountingPoliciesDetails4" />
  <link:roleRef roleURI="http://www.2u.com/role/DisclosureWarrantsDetails" xlink:type="simple" xlink:href="twou-20140630.xsd#DisclosureWarrantsDetails" />
  <link:roleRef roleURI="http://www.2u.com/role/DisclosureNetLossPerShareDetails2" xlink:type="simple" xlink:href="twou-20140630.xsd#DisclosureNetLossPerShareDetails2" />
  <link:roleRef roleURI="http://www.2u.com/role/DisclosurePropertyAndEquipmentDetails" xlink:type="simple" xlink:href="twou-20140630.xsd#DisclosurePropertyAndEquipmentDetails" />
  <link:roleRef roleURI="http://www.2u.com/role/DisclosureFairValueMeasurementsDetails" xlink:type="simple" xlink:href="twou-20140630.xsd#DisclosureFairValueMeasurementsDetails" />
  <link:roleRef roleURI="http://www.2u.com/role/DisclosureRedeemableConvertiblePreferredStockDetails" xlink:type="simple" xlink:href="twou-20140630.xsd#DisclosureRedeemableConvertiblePreferredStockDetails" />
  <link:roleRef roleURI="http://www.2u.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails7" xlink:type="simple" xlink:href="twou-20140630.xsd#DisclosureSummaryOfSignificantAccountingPoliciesDetails7" />
  <link:roleRef roleURI="http://www.2u.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails5" xlink:type="simple" xlink:href="twou-20140630.xsd#DisclosureSummaryOfSignificantAccountingPoliciesDetails5" />
  <link:roleRef roleURI="http://www.2u.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails2" xlink:type="simple" xlink:href="twou-20140630.xsd#DisclosureSummaryOfSignificantAccountingPoliciesDetails2" />
  <link:roleRef roleURI="http://www.2u.com/role/DisclosureNetLossPerShareDetails" xlink:type="simple" xlink:href="twou-20140630.xsd#DisclosureNetLossPerShareDetails" />
  <link:roleRef roleURI="http://www.2u.com/role/DisclosureSubsequentEventsDetails" xlink:type="simple" xlink:href="twou-20140630.xsd#DisclosureSubsequentEventsDetails" />
  <link:roleRef roleURI="http://www.2u.com/role/DisclosureStockBasedCompensationDetail2" xlink:type="simple" xlink:href="twou-20140630.xsd#DisclosureStockBasedCompensationDetail2" />
  <link:roleRef roleURI="http://www.2u.com/role/DisclosureNetLossPerShareTables" xlink:type="simple" xlink:href="twou-20140630.xsd#DisclosureNetLossPerShareTables" />
  <link:roleRef roleURI="http://www.2u.com/role/DisclosureStockBasedCompensationDetails" xlink:type="simple" xlink:href="twou-20140630.xsd#DisclosureStockBasedCompensationDetails" />
  <link:roleRef roleURI="http://www.2u.com/role/BalanceSheetParenthetical" xlink:type="simple" xlink:href="twou-20140630.xsd#BalanceSheetParenthetical" />
  <link:roleRef roleURI="http://www.2u.com/role/BalanceSheet" xlink:type="simple" xlink:href="twou-20140630.xsd#BalanceSheet" />
  <link:roleRef roleURI="http://www.2u.com/role/StatementOfStockholdersEquity" xlink:type="simple" xlink:href="twou-20140630.xsd#StatementOfStockholdersEquity" />
  <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/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: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:definitionLink xlink:type="extended" xlink:role="http://www.2u.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails3">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ConcentrationRiskLineItems" xlink:label="ConcentrationRiskLineItems" xlink:title="ConcentrationRiskLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ConcentrationRiskTable" xlink:label="ConcentrationRiskTable" xlink:title="ConcentrationRiskTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="ConcentrationRiskLineItems" xlink:to="ConcentrationRiskTable" xlink:title="definition: ConcentrationRiskLineItems to ConcentrationRiskTable" use="optional" order="1.0" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:label="ConcentrationRiskByBenchmarkAxis" xlink:title="ConcentrationRiskByBenchmarkAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ConcentrationRiskTable" xlink:to="ConcentrationRiskByBenchmarkAxis" xlink:title="definition: ConcentrationRiskTable to ConcentrationRiskByBenchmarkAxis" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:label="ConcentrationRiskBenchmarkDomain" xlink:title="ConcentrationRiskBenchmarkDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="ConcentrationRiskByBenchmarkAxis" xlink:to="ConcentrationRiskBenchmarkDomain" xlink:title="definition: ConcentrationRiskByBenchmarkAxis to ConcentrationRiskBenchmarkDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:label="ConcentrationRiskBenchmarkDomain_2" xlink:title="ConcentrationRiskBenchmarkDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="ConcentrationRiskByBenchmarkAxis" xlink:to="ConcentrationRiskBenchmarkDomain_2" xlink:title="definition: ConcentrationRiskByBenchmarkAxis to ConcentrationRiskBenchmarkDomain" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SalesRevenueServicesNetMember" xlink:label="SalesRevenueServicesNetMember" xlink:title="SalesRevenueServicesNetMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ConcentrationRiskBenchmarkDomain" xlink:to="SalesRevenueServicesNetMember" xlink:title="definition: ConcentrationRiskBenchmarkDomain to SalesRevenueServicesNetMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccountsReceivableMember" xlink:label="AccountsReceivableMember" xlink:title="AccountsReceivableMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ConcentrationRiskBenchmarkDomain" xlink:to="AccountsReceivableMember" xlink:title="definition: ConcentrationRiskBenchmarkDomain to AccountsReceivableMember" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ConcentrationRiskByTypeAxis" xlink:label="ConcentrationRiskByTypeAxis" xlink:title="ConcentrationRiskByTypeAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ConcentrationRiskTable" xlink:to="ConcentrationRiskByTypeAxis" xlink:title="definition: ConcentrationRiskTable to ConcentrationRiskByTypeAxis" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="ConcentrationRiskTypeDomain" xlink:title="ConcentrationRiskTypeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="ConcentrationRiskByTypeAxis" xlink:to="ConcentrationRiskTypeDomain" xlink:title="definition: ConcentrationRiskByTypeAxis to ConcentrationRiskTypeDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:label="ConcentrationRiskTypeDomain_2" xlink:title="ConcentrationRiskTypeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="ConcentrationRiskByTypeAxis" xlink:to="ConcentrationRiskTypeDomain_2" xlink:title="definition: ConcentrationRiskByTypeAxis to ConcentrationRiskTypeDomain" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CustomerConcentrationRiskMember" xlink:label="CustomerConcentrationRiskMember" xlink:title="CustomerConcentrationRiskMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ConcentrationRiskTypeDomain" xlink:to="CustomerConcentrationRiskMember" xlink:title="definition: ConcentrationRiskTypeDomain to CustomerConcentrationRiskMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CreditConcentrationRiskMember" xlink:label="CreditConcentrationRiskMember" xlink:title="CreditConcentrationRiskMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ConcentrationRiskTypeDomain" xlink:to="CreditConcentrationRiskMember" xlink:title="definition: ConcentrationRiskTypeDomain to CreditConcentrationRiskMember" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_TypeOfContractAxis" xlink:label="TypeOfContractAxis" xlink:title="TypeOfContractAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ConcentrationRiskTable" xlink:to="TypeOfContractAxis" xlink:title="definition: ConcentrationRiskTable to TypeOfContractAxis" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_TypeOfContractDomain" xlink:label="TypeOfContractDomain" xlink:title="TypeOfContractDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="TypeOfContractAxis" xlink:to="TypeOfContractDomain" xlink:title="definition: TypeOfContractAxis to TypeOfContractDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_TypeOfContractDomain" xlink:label="TypeOfContractDomain_2" xlink:title="TypeOfContractDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="TypeOfContractAxis" xlink:to="TypeOfContractDomain_2" xlink:title="definition: TypeOfContractAxis to TypeOfContractDomain" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_TwoContractsWithSameUniversityMember" xlink:label="TwoContractsWithSameUniversityMember" xlink:title="TwoContractsWithSameUniversityMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="TypeOfContractDomain" xlink:to="TwoContractsWithSameUniversityMember" xlink:title="definition: TypeOfContractDomain to TwoContractsWithSameUniversityMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_OneContractWithUniversityMember" xlink:label="OneContractWithUniversityMember" xlink:title="OneContractWithUniversityMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="TypeOfContractDomain" xlink:to="OneContractWithUniversityMember" xlink:title="definition: TypeOfContractDomain to OneContractWithUniversityMember" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ConcentrationRiskPercentage1" xlink:label="ConcentrationRiskPercentage1" xlink:title="ConcentrationRiskPercentage1" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ConcentrationRiskLineItems" xlink:to="ConcentrationRiskPercentage1" xlink:title="definition: ConcentrationRiskLineItems to ConcentrationRiskPercentage1" use="optional" order="2.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.2u.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails4">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="PropertyPlantAndEquipmentLineItems" xlink:title="PropertyPlantAndEquipmentLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="ScheduleOfPropertyPlantAndEquipmentTable" xlink:title="ScheduleOfPropertyPlantAndEquipmentTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="PropertyPlantAndEquipmentLineItems" xlink:to="ScheduleOfPropertyPlantAndEquipmentTable" xlink:title="definition: PropertyPlantAndEquipmentLineItems to ScheduleOfPropertyPlantAndEquipmentTable" use="optional" order="1.0" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="PropertyPlantAndEquipmentByTypeAxis" xlink:title="PropertyPlantAndEquipmentByTypeAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfPropertyPlantAndEquipmentTable" xlink:to="PropertyPlantAndEquipmentByTypeAxis" xlink:title="definition: ScheduleOfPropertyPlantAndEquipmentTable to PropertyPlantAndEquipmentByTypeAxis" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="PropertyPlantAndEquipmentTypeDomain" xlink:title="PropertyPlantAndEquipmentTypeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="PropertyPlantAndEquipmentByTypeAxis" xlink:to="PropertyPlantAndEquipmentTypeDomain" xlink:title="definition: PropertyPlantAndEquipmentByTypeAxis to PropertyPlantAndEquipmentTypeDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ComputerEquipmentMember" xlink:label="ComputerEquipmentMember" xlink:title="ComputerEquipmentMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="PropertyPlantAndEquipmentTypeDomain" xlink:to="ComputerEquipmentMember" xlink:title="definition: PropertyPlantAndEquipmentTypeDomain to ComputerEquipmentMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FurnitureAndFixturesMember" xlink:label="FurnitureAndFixturesMember" xlink:title="FurnitureAndFixturesMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="PropertyPlantAndEquipmentTypeDomain" xlink:to="FurnitureAndFixturesMember" xlink:title="definition: PropertyPlantAndEquipmentTypeDomain to FurnitureAndFixturesMember" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LeaseholdImprovementsMember" xlink:label="LeaseholdImprovementsMember" xlink:title="LeaseholdImprovementsMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="PropertyPlantAndEquipmentTypeDomain" xlink:to="LeaseholdImprovementsMember" xlink:title="definition: PropertyPlantAndEquipmentTypeDomain to LeaseholdImprovementsMember" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SoftwareDevelopmentMember" xlink:label="SoftwareDevelopmentMember" xlink:title="SoftwareDevelopmentMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="PropertyPlantAndEquipmentTypeDomain" xlink:to="SoftwareDevelopmentMember" xlink:title="definition: PropertyPlantAndEquipmentTypeDomain to SoftwareDevelopmentMember" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeAxis" xlink:label="RangeAxis" xlink:title="RangeAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfPropertyPlantAndEquipmentTable" xlink:to="RangeAxis" xlink:title="definition: ScheduleOfPropertyPlantAndEquipmentTable to RangeAxis" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeMember" xlink:label="RangeMember" xlink:title="RangeMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="RangeAxis" xlink:to="RangeMember" xlink:title="definition: RangeAxis to RangeMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MinimumMember" xlink:label="MinimumMember" xlink:title="MinimumMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="RangeMember" xlink:to="MinimumMember" xlink:title="definition: RangeMember to MinimumMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MaximumMember" xlink:label="MaximumMember" xlink:title="MaximumMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="RangeMember" xlink:to="MaximumMember" xlink:title="definition: RangeMember to MaximumMember" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:label="PropertyPlantAndEquipmentUsefulLife" xlink:title="PropertyPlantAndEquipmentUsefulLife" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="PropertyPlantAndEquipmentLineItems" xlink:to="PropertyPlantAndEquipmentUsefulLife" xlink:title="definition: PropertyPlantAndEquipmentLineItems to PropertyPlantAndEquipmentUsefulLife" use="optional" order="2.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.2u.com/role/DisclosureWarrantsDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfWarrantOrRightLineItems" xlink:label="ClassOfWarrantOrRightLineItems" xlink:title="ClassOfWarrantOrRightLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfWarrantOrRightTable" xlink:label="ClassOfWarrantOrRightTable" xlink:title="ClassOfWarrantOrRightTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="ClassOfWarrantOrRightLineItems" xlink:to="ClassOfWarrantOrRightTable" xlink:title="definition: ClassOfWarrantOrRightLineItems to ClassOfWarrantOrRightTable" use="optional" order="1.0" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfWarrantOrRightAxis" xlink:label="ClassOfWarrantOrRightAxis" xlink:title="ClassOfWarrantOrRightAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ClassOfWarrantOrRightTable" xlink:to="ClassOfWarrantOrRightAxis" xlink:title="definition: ClassOfWarrantOrRightTable to ClassOfWarrantOrRightAxis" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfWarrantOrRightDomain" xlink:label="ClassOfWarrantOrRightDomain" xlink:title="ClassOfWarrantOrRightDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="ClassOfWarrantOrRightAxis" xlink:to="ClassOfWarrantOrRightDomain" xlink:title="definition: ClassOfWarrantOrRightAxis to ClassOfWarrantOrRightDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfWarrantOrRightDomain" xlink:label="ClassOfWarrantOrRightDomain_2" xlink:title="ClassOfWarrantOrRightDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="ClassOfWarrantOrRightAxis" xlink:to="ClassOfWarrantOrRightDomain_2" xlink:title="definition: ClassOfWarrantOrRightAxis to ClassOfWarrantOrRightDomain" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_WarrantToPurchaseSeriesDRedeemableConvertiblePreferredStockExpiringIn2022Member" xlink:label="WarrantToPurchaseSeriesDRedeemableConvertiblePreferredStockExpiringIn2022Member" xlink:title="WarrantToPurchaseSeriesDRedeemableConvertiblePreferredStockExpiringIn2022Member" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfWarrantOrRightDomain" xlink:to="WarrantToPurchaseSeriesDRedeemableConvertiblePreferredStockExpiringIn2022Member" xlink:title="definition: ClassOfWarrantOrRightDomain to WarrantToPurchaseSeriesDRedeemableConvertiblePreferredStockExpiringIn2022Member" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_WarrantToPurchaseSeriesDRedeemableConvertiblePreferredStockExpiringIn2023Member" xlink:label="WarrantToPurchaseSeriesDRedeemableConvertiblePreferredStockExpiringIn2023Member" xlink:title="WarrantToPurchaseSeriesDRedeemableConvertiblePreferredStockExpiringIn2023Member" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfWarrantOrRightDomain" xlink:to="WarrantToPurchaseSeriesDRedeemableConvertiblePreferredStockExpiringIn2023Member" xlink:title="definition: ClassOfWarrantOrRightDomain to WarrantToPurchaseSeriesDRedeemableConvertiblePreferredStockExpiringIn2023Member" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="SubsequentEventTypeAxis" xlink:title="SubsequentEventTypeAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ClassOfWarrantOrRightTable" xlink:to="SubsequentEventTypeAxis" xlink:title="definition: ClassOfWarrantOrRightTable to SubsequentEventTypeAxis" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="SubsequentEventTypeDomain" xlink:title="SubsequentEventTypeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="SubsequentEventTypeAxis" xlink:to="SubsequentEventTypeDomain" xlink:title="definition: SubsequentEventTypeAxis to SubsequentEventTypeDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SubsequentEventMember" xlink:label="SubsequentEventMember" xlink:title="SubsequentEventMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SubsequentEventTypeDomain" xlink:to="SubsequentEventMember" xlink:title="definition: SubsequentEventTypeDomain to SubsequentEventMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="StatementClassOfStockAxis" xlink:title="StatementClassOfStockAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ClassOfWarrantOrRightTable" xlink:to="StatementClassOfStockAxis" xlink:title="definition: ClassOfWarrantOrRightTable to StatementClassOfStockAxis" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="ClassOfStockDomain" xlink:title="ClassOfStockDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="StatementClassOfStockAxis" xlink:to="ClassOfStockDomain" xlink:title="definition: StatementClassOfStockAxis to ClassOfStockDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_RedeemableConvertibleSeriesCPreferredStockMember" xlink:label="RedeemableConvertibleSeriesCPreferredStockMember" xlink:title="RedeemableConvertibleSeriesCPreferredStockMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfStockDomain" xlink:to="RedeemableConvertibleSeriesCPreferredStockMember" xlink:title="definition: ClassOfStockDomain to RedeemableConvertibleSeriesCPreferredStockMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" xlink:label="ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" xlink:title="ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfWarrantOrRightLineItems" xlink:to="ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" xlink:title="definition: ClassOfWarrantOrRightLineItems to ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights" xlink:label="ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights" xlink:title="ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfWarrantOrRightLineItems" xlink:to="ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights" xlink:title="definition: ClassOfWarrantOrRightLineItems to ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_WarrantsNotSettleableInCashFairValueDisclosure" xlink:label="WarrantsNotSettleableInCashFairValueDisclosure" xlink:title="WarrantsNotSettleableInCashFairValueDisclosure" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfWarrantOrRightLineItems" xlink:to="WarrantsNotSettleableInCashFairValueDisclosure" xlink:title="definition: ClassOfWarrantOrRightLineItems to WarrantsNotSettleableInCashFairValueDisclosure" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_ClassOfWarrantOrRightAmountReclassifiedToAdditionalPaidInCapitalOnConversionOfWarrants" xlink:label="ClassOfWarrantOrRightAmountReclassifiedToAdditionalPaidInCapitalOnConversionOfWarrants" xlink:title="ClassOfWarrantOrRightAmountReclassifiedToAdditionalPaidInCapitalOnConversionOfWarrants" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfWarrantOrRightLineItems" xlink:to="ClassOfWarrantOrRightAmountReclassifiedToAdditionalPaidInCapitalOnConversionOfWarrants" xlink:title="definition: ClassOfWarrantOrRightLineItems to ClassOfWarrantOrRightAmountReclassifiedToAdditionalPaidInCapitalOnConversionOfWarrants" use="optional" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAdjustmentOfWarrants" xlink:label="FairValueAdjustmentOfWarrants" xlink:title="FairValueAdjustmentOfWarrants" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfWarrantOrRightLineItems" xlink:to="FairValueAdjustmentOfWarrants" xlink:title="definition: ClassOfWarrantOrRightLineItems to FairValueAdjustmentOfWarrants" use="optional" order="6.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_InterestExpenseOnFairValueAdjustmentOfWarrants" xlink:label="InterestExpenseOnFairValueAdjustmentOfWarrants" xlink:title="InterestExpenseOnFairValueAdjustmentOfWarrants" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfWarrantOrRightLineItems" xlink:to="InterestExpenseOnFairValueAdjustmentOfWarrants" xlink:title="definition: ClassOfWarrantOrRightLineItems to InterestExpenseOnFairValueAdjustmentOfWarrants" use="optional" order="7.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_SharesToBePurchasedOnIssueOfExerciseNoticeByHolderOfWarrants" xlink:label="SharesToBePurchasedOnIssueOfExerciseNoticeByHolderOfWarrants" xlink:title="SharesToBePurchasedOnIssueOfExerciseNoticeByHolderOfWarrants" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfWarrantOrRightLineItems" xlink:to="SharesToBePurchasedOnIssueOfExerciseNoticeByHolderOfWarrants" xlink:title="definition: ClassOfWarrantOrRightLineItems to SharesToBePurchasedOnIssueOfExerciseNoticeByHolderOfWarrants" use="optional" order="8.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_NumberOfTradingDaysConsideredInVolumeWeightedAveragePriceOfCommonStock" xlink:label="NumberOfTradingDaysConsideredInVolumeWeightedAveragePriceOfCommonStock" xlink:title="NumberOfTradingDaysConsideredInVolumeWeightedAveragePriceOfCommonStock" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfWarrantOrRightLineItems" xlink:to="NumberOfTradingDaysConsideredInVolumeWeightedAveragePriceOfCommonStock" xlink:title="definition: ClassOfWarrantOrRightLineItems to NumberOfTradingDaysConsideredInVolumeWeightedAveragePriceOfCommonStock" use="optional" order="9.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_StockIssuedDuringPeriodSharesExerciseOfWarrantsToPurchaseCommonStock" xlink:label="StockIssuedDuringPeriodSharesExerciseOfWarrantsToPurchaseCommonStock" xlink:title="StockIssuedDuringPeriodSharesExerciseOfWarrantsToPurchaseCommonStock" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfWarrantOrRightLineItems" xlink:to="StockIssuedDuringPeriodSharesExerciseOfWarrantsToPurchaseCommonStock" xlink:title="definition: ClassOfWarrantOrRightLineItems to StockIssuedDuringPeriodSharesExerciseOfWarrantsToPurchaseCommonStock" use="optional" order="10.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_WarrantsAndRightsOutstanding" xlink:label="WarrantsAndRightsOutstanding" xlink:title="WarrantsAndRightsOutstanding" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfWarrantOrRightLineItems" xlink:to="WarrantsAndRightsOutstanding" xlink:title="definition: ClassOfWarrantOrRightLineItems to WarrantsAndRightsOutstanding" use="optional" order="11.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.2u.com/role/DisclosureNetLossPerShareDetails2">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="StatementLineItems" xlink:title="StatementLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable" xlink:label="ScheduleOfEarningsPerShareBasicByCommonClassTable" xlink:title="ScheduleOfEarningsPerShareBasicByCommonClassTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="StatementLineItems" xlink:to="ScheduleOfEarningsPerShareBasicByCommonClassTable" xlink:title="definition: StatementLineItems to ScheduleOfEarningsPerShareBasicByCommonClassTable" use="optional" order="1.0" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="StatementScenarioAxis" xlink:title="StatementScenarioAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfEarningsPerShareBasicByCommonClassTable" xlink:to="StatementScenarioAxis" xlink:title="definition: ScheduleOfEarningsPerShareBasicByCommonClassTable to StatementScenarioAxis" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="ScenarioUnspecifiedDomain" xlink:title="ScenarioUnspecifiedDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="StatementScenarioAxis" xlink:to="ScenarioUnspecifiedDomain" xlink:title="definition: StatementScenarioAxis to ScenarioUnspecifiedDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProFormaMember" xlink:label="ProFormaMember" xlink:title="ProFormaMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ScenarioUnspecifiedDomain" xlink:to="ProFormaMember" xlink:title="definition: ScenarioUnspecifiedDomain to ProFormaMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasicAbstract" xlink:label="NetIncomeLossAvailableToCommonStockholdersBasicAbstract" xlink:title="NetIncomeLossAvailableToCommonStockholdersBasicAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="NetIncomeLossAvailableToCommonStockholdersBasicAbstract" xlink:title="definition: StatementLineItems to NetIncomeLossAvailableToCommonStockholdersBasicAbstract" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic" xlink:label="NetIncomeLossAvailableToCommonStockholdersBasic" xlink:title="NetIncomeLossAvailableToCommonStockholdersBasic" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="NetIncomeLossAvailableToCommonStockholdersBasicAbstract" xlink:to="NetIncomeLossAvailableToCommonStockholdersBasic" xlink:title="definition: NetIncomeLossAvailableToCommonStockholdersBasicAbstract to NetIncomeLossAvailableToCommonStockholdersBasic" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_OtherPreferredStockDividendsAndAdjustment" xlink:label="OtherPreferredStockDividendsAndAdjustment" xlink:title="OtherPreferredStockDividendsAndAdjustment" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="NetIncomeLossAvailableToCommonStockholdersBasicAbstract" xlink:to="OtherPreferredStockDividendsAndAdjustment" xlink:title="definition: NetIncomeLossAvailableToCommonStockholdersBasicAbstract to OtherPreferredStockDividendsAndAdjustment" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_WeightedAverageNumberOfShareOutstandingBasicAndDilutedAbstract" xlink:label="WeightedAverageNumberOfShareOutstandingBasicAndDilutedAbstract" xlink:title="WeightedAverageNumberOfShareOutstandingBasicAndDilutedAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="WeightedAverageNumberOfShareOutstandingBasicAndDilutedAbstract" xlink:title="definition: StatementLineItems to WeightedAverageNumberOfShareOutstandingBasicAndDilutedAbstract" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" xlink:label="WeightedAverageNumberOfShareOutstandingBasicAndDiluted" xlink:title="WeightedAverageNumberOfShareOutstandingBasicAndDiluted" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="WeightedAverageNumberOfShareOutstandingBasicAndDilutedAbstract" xlink:to="WeightedAverageNumberOfShareOutstandingBasicAndDiluted" xlink:title="definition: WeightedAverageNumberOfShareOutstandingBasicAndDilutedAbstract to WeightedAverageNumberOfShareOutstandingBasicAndDiluted" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncrementalCommonSharesAttributableToConversionOfPreferredStock" xlink:label="IncrementalCommonSharesAttributableToConversionOfPreferredStock" xlink:title="IncrementalCommonSharesAttributableToConversionOfPreferredStock" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="WeightedAverageNumberOfShareOutstandingBasicAndDilutedAbstract" xlink:to="IncrementalCommonSharesAttributableToConversionOfPreferredStock" xlink:title="definition: WeightedAverageNumberOfShareOutstandingBasicAndDilutedAbstract to IncrementalCommonSharesAttributableToConversionOfPreferredStock" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_WeightedAverageBasicAndDilutedSharesOutstandingProForma" xlink:label="WeightedAverageBasicAndDilutedSharesOutstandingProForma" xlink:title="WeightedAverageBasicAndDilutedSharesOutstandingProForma" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="WeightedAverageNumberOfShareOutstandingBasicAndDilutedAbstract" xlink:to="WeightedAverageBasicAndDilutedSharesOutstandingProForma" xlink:title="definition: WeightedAverageNumberOfShareOutstandingBasicAndDilutedAbstract to WeightedAverageBasicAndDilutedSharesOutstandingProForma" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EarningsPerShareBasicAndDiluted" xlink:label="EarningsPerShareBasicAndDiluted" xlink:title="EarningsPerShareBasicAndDiluted" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="EarningsPerShareBasicAndDiluted" xlink:title="definition: StatementLineItems to EarningsPerShareBasicAndDiluted" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EarningsPerShareProFormaAbstract" xlink:label="EarningsPerShareProFormaAbstract" xlink:title="EarningsPerShareProFormaAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="EarningsPerShareProFormaAbstract" xlink:title="definition: StatementLineItems to EarningsPerShareProFormaAbstract" use="optional" order="5.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.2u.com/role/DisclosurePropertyAndEquipmentDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="PropertyPlantAndEquipmentLineItems" xlink:title="PropertyPlantAndEquipmentLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="ScheduleOfPropertyPlantAndEquipmentTable" xlink:title="ScheduleOfPropertyPlantAndEquipmentTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="PropertyPlantAndEquipmentLineItems" xlink:to="ScheduleOfPropertyPlantAndEquipmentTable" xlink:title="definition: PropertyPlantAndEquipmentLineItems to ScheduleOfPropertyPlantAndEquipmentTable" use="optional" order="1.0" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="PropertyPlantAndEquipmentByTypeAxis" xlink:title="PropertyPlantAndEquipmentByTypeAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfPropertyPlantAndEquipmentTable" xlink:to="PropertyPlantAndEquipmentByTypeAxis" xlink:title="definition: ScheduleOfPropertyPlantAndEquipmentTable to PropertyPlantAndEquipmentByTypeAxis" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="PropertyPlantAndEquipmentTypeDomain" xlink:title="PropertyPlantAndEquipmentTypeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="PropertyPlantAndEquipmentByTypeAxis" xlink:to="PropertyPlantAndEquipmentTypeDomain" xlink:title="definition: PropertyPlantAndEquipmentByTypeAxis to PropertyPlantAndEquipmentTypeDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="PropertyPlantAndEquipmentTypeDomain_2" xlink:title="PropertyPlantAndEquipmentTypeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="PropertyPlantAndEquipmentByTypeAxis" xlink:to="PropertyPlantAndEquipmentTypeDomain_2" xlink:title="definition: PropertyPlantAndEquipmentByTypeAxis to PropertyPlantAndEquipmentTypeDomain" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ComputerEquipmentMember" xlink:label="ComputerEquipmentMember" xlink:title="ComputerEquipmentMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="PropertyPlantAndEquipmentTypeDomain" xlink:to="ComputerEquipmentMember" xlink:title="definition: PropertyPlantAndEquipmentTypeDomain to ComputerEquipmentMember" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FurnitureAndFixturesMember" xlink:label="FurnitureAndFixturesMember" xlink:title="FurnitureAndFixturesMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="PropertyPlantAndEquipmentTypeDomain" xlink:to="FurnitureAndFixturesMember" xlink:title="definition: PropertyPlantAndEquipmentTypeDomain to FurnitureAndFixturesMember" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LeaseholdImprovementsMember" xlink:label="LeaseholdImprovementsMember" xlink:title="LeaseholdImprovementsMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="PropertyPlantAndEquipmentTypeDomain" xlink:to="LeaseholdImprovementsMember" xlink:title="definition: PropertyPlantAndEquipmentTypeDomain to LeaseholdImprovementsMember" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SoftwareDevelopmentMember" xlink:label="SoftwareDevelopmentMember" xlink:title="SoftwareDevelopmentMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="PropertyPlantAndEquipmentTypeDomain" xlink:to="SoftwareDevelopmentMember" xlink:title="definition: PropertyPlantAndEquipmentTypeDomain to SoftwareDevelopmentMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="PropertyPlantAndEquipmentGross" xlink:title="PropertyPlantAndEquipmentGross" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="PropertyPlantAndEquipmentLineItems" xlink:to="PropertyPlantAndEquipmentGross" xlink:title="definition: PropertyPlantAndEquipmentLineItems to PropertyPlantAndEquipmentGross" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:title="AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="PropertyPlantAndEquipmentLineItems" xlink:to="AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:title="definition: PropertyPlantAndEquipmentLineItems to AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="PropertyPlantAndEquipmentNet" xlink:title="PropertyPlantAndEquipmentNet" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="PropertyPlantAndEquipmentLineItems" xlink:to="PropertyPlantAndEquipmentNet" xlink:title="definition: PropertyPlantAndEquipmentLineItems to PropertyPlantAndEquipmentNet" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_Depreciation" xlink:label="Depreciation" xlink:title="Depreciation" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="PropertyPlantAndEquipmentLineItems" xlink:to="Depreciation" xlink:title="definition: PropertyPlantAndEquipmentLineItems to Depreciation" use="optional" order="5.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.2u.com/role/DisclosureFairValueMeasurementsDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:label="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:title="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:title="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:title="definition: FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems to FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" use="optional" order="1.0" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueByMeasurementFrequencyAxis" xlink:label="FairValueByMeasurementFrequencyAxis" xlink:title="FairValueByMeasurementFrequencyAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="FairValueByMeasurementFrequencyAxis" xlink:title="definition: FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable to FairValueByMeasurementFrequencyAxis" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="FairValueMeasurementFrequencyDomain" xlink:title="FairValueMeasurementFrequencyDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="FairValueByMeasurementFrequencyAxis" xlink:to="FairValueMeasurementFrequencyDomain" xlink:title="definition: FairValueByMeasurementFrequencyAxis to FairValueMeasurementFrequencyDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="FairValueMeasurementFrequencyDomain_2" xlink:title="FairValueMeasurementFrequencyDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="FairValueByMeasurementFrequencyAxis" xlink:to="FairValueMeasurementFrequencyDomain_2" xlink:title="definition: FairValueByMeasurementFrequencyAxis to FairValueMeasurementFrequencyDomain" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementsRecurringMember" xlink:label="FairValueMeasurementsRecurringMember" xlink:title="FairValueMeasurementsRecurringMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="FairValueMeasurementFrequencyDomain" xlink:to="FairValueMeasurementsRecurringMember" xlink:title="definition: FairValueMeasurementFrequencyDomain to FairValueMeasurementsRecurringMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="FairValueByFairValueHierarchyLevelAxis" xlink:title="FairValueByFairValueHierarchyLevelAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="FairValueByFairValueHierarchyLevelAxis" xlink:title="definition: FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable to FairValueByFairValueHierarchyLevelAxis" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="FairValueMeasurementsFairValueHierarchyDomain" xlink:title="FairValueMeasurementsFairValueHierarchyDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="FairValueByFairValueHierarchyLevelAxis" xlink:to="FairValueMeasurementsFairValueHierarchyDomain" xlink:title="definition: FairValueByFairValueHierarchyLevelAxis to FairValueMeasurementsFairValueHierarchyDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="FairValueMeasurementsFairValueHierarchyDomain_2" xlink:title="FairValueMeasurementsFairValueHierarchyDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="FairValueByFairValueHierarchyLevelAxis" xlink:to="FairValueMeasurementsFairValueHierarchyDomain_2" xlink:title="definition: FairValueByFairValueHierarchyLevelAxis to FairValueMeasurementsFairValueHierarchyDomain" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EstimateOfFairValueFairValueDisclosureMember" xlink:label="EstimateOfFairValueFairValueDisclosureMember" xlink:title="EstimateOfFairValueFairValueDisclosureMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="FairValueMeasurementsFairValueHierarchyDomain" xlink:to="EstimateOfFairValueFairValueDisclosureMember" xlink:title="definition: FairValueMeasurementsFairValueHierarchyDomain to EstimateOfFairValueFairValueDisclosureMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="FairValueInputsLevel1Member" xlink:title="FairValueInputsLevel1Member" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="FairValueMeasurementsFairValueHierarchyDomain" xlink:to="FairValueInputsLevel1Member" xlink:title="definition: FairValueMeasurementsFairValueHierarchyDomain to FairValueInputsLevel1Member" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="FairValueInputsLevel3Member" xlink:title="FairValueInputsLevel3Member" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="FairValueMeasurementsFairValueHierarchyDomain" xlink:to="FairValueInputsLevel3Member" xlink:title="definition: FairValueMeasurementsFairValueHierarchyDomain to FairValueInputsLevel3Member" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="FairValueInputsLevel2Member" xlink:title="FairValueInputsLevel2Member" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="FairValueMeasurementsFairValueHierarchyDomain" xlink:to="FairValueInputsLevel2Member" xlink:title="definition: FairValueMeasurementsFairValueHierarchyDomain to FairValueInputsLevel2Member" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AssetsFairValueDisclosureAbstract" xlink:label="AssetsFairValueDisclosureAbstract" xlink:title="AssetsFairValueDisclosureAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="AssetsFairValueDisclosureAbstract" xlink:title="definition: FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems to AssetsFairValueDisclosureAbstract" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure" xlink:label="CashAndCashEquivalentsFairValueDisclosure" xlink:title="CashAndCashEquivalentsFairValueDisclosure" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="AssetsFairValueDisclosureAbstract" xlink:to="CashAndCashEquivalentsFairValueDisclosure" xlink:title="definition: AssetsFairValueDisclosureAbstract to CashAndCashEquivalentsFairValueDisclosure" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LiabilitiesFairValueDisclosureAbstract" xlink:label="LiabilitiesFairValueDisclosureAbstract" xlink:title="LiabilitiesFairValueDisclosureAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="LiabilitiesFairValueDisclosureAbstract" xlink:title="definition: FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems to LiabilitiesFairValueDisclosureAbstract" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_WarrantsNotSettleableInCashFairValueDisclosure" xlink:label="WarrantsNotSettleableInCashFairValueDisclosure" xlink:title="WarrantsNotSettleableInCashFairValueDisclosure" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LiabilitiesFairValueDisclosureAbstract" xlink:to="WarrantsNotSettleableInCashFairValueDisclosure" xlink:title="definition: LiabilitiesFairValueDisclosureAbstract to WarrantsNotSettleableInCashFairValueDisclosure" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" xlink:label="FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" xlink:title="FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" xlink:title="definition: FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems to FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward" use="optional" order="4.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.2u.com/role/DisclosureRedeemableConvertiblePreferredStockDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="SubsequentEventTypeAxis" xlink:title="SubsequentEventTypeAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="SubsequentEventTypeDomain" xlink:title="SubsequentEventTypeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="SubsequentEventTypeAxis" xlink:to="SubsequentEventTypeDomain" xlink:title="definition: SubsequentEventTypeAxis to SubsequentEventTypeDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SubsequentEventMember" xlink:label="SubsequentEventMember" xlink:title="SubsequentEventMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SubsequentEventTypeDomain" xlink:to="SubsequentEventMember" xlink:title="definition: SubsequentEventTypeDomain to SubsequentEventMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="StatementClassOfStockAxis" xlink:title="StatementClassOfStockAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="ClassOfStockDomain" xlink:title="ClassOfStockDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="StatementClassOfStockAxis" xlink:to="ClassOfStockDomain" xlink:title="definition: StatementClassOfStockAxis to ClassOfStockDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_RedeemableConvertibleSeriesCPreferredStockMember" xlink:label="RedeemableConvertibleSeriesCPreferredStockMember" xlink:title="RedeemableConvertibleSeriesCPreferredStockMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfStockDomain" xlink:to="RedeemableConvertibleSeriesCPreferredStockMember" xlink:title="definition: ClassOfStockDomain to RedeemableConvertibleSeriesCPreferredStockMember" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_RedeemableConvertibleSeriesAPreferredStockMember" xlink:label="RedeemableConvertibleSeriesAPreferredStockMember" xlink:title="RedeemableConvertibleSeriesAPreferredStockMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfStockDomain" xlink:to="RedeemableConvertibleSeriesAPreferredStockMember" xlink:title="definition: ClassOfStockDomain to RedeemableConvertibleSeriesAPreferredStockMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_RedeemableConvertibleSeriesBPreferredStockMember" xlink:label="RedeemableConvertibleSeriesBPreferredStockMember" xlink:title="RedeemableConvertibleSeriesBPreferredStockMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfStockDomain" xlink:to="RedeemableConvertibleSeriesBPreferredStockMember" xlink:title="definition: ClassOfStockDomain to RedeemableConvertibleSeriesBPreferredStockMember" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_RedeemableConvertibleSeriesDPreferredStockMember" xlink:label="RedeemableConvertibleSeriesDPreferredStockMember" xlink:title="RedeemableConvertibleSeriesDPreferredStockMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfStockDomain" xlink:to="RedeemableConvertibleSeriesDPreferredStockMember" xlink:title="definition: ClassOfStockDomain to RedeemableConvertibleSeriesDPreferredStockMember" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TemporaryEquityLineItems" xlink:label="TemporaryEquityLineItems" xlink:title="TemporaryEquityLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TemporaryEquityByClassOfStockTable" xlink:label="TemporaryEquityByClassOfStockTable" xlink:title="TemporaryEquityByClassOfStockTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="TemporaryEquityLineItems" xlink:to="TemporaryEquityByClassOfStockTable" xlink:title="definition: TemporaryEquityLineItems to TemporaryEquityByClassOfStockTable" use="optional" order="1.0" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="TemporaryEquityByClassOfStockTable" xlink:to="StatementClassOfStockAxis" xlink:title="definition: TemporaryEquityByClassOfStockTable to StatementClassOfStockAxis" use="optional" order="1.0" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="TemporaryEquityByClassOfStockTable" xlink:to="SubsequentEventTypeAxis" xlink:title="definition: TemporaryEquityByClassOfStockTable to SubsequentEventTypeAxis" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharesIssuedPricePerShare" xlink:label="SharesIssuedPricePerShare" xlink:title="SharesIssuedPricePerShare" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="TemporaryEquityLineItems" xlink:to="SharesIssuedPricePerShare" xlink:title="definition: TemporaryEquityLineItems to SharesIssuedPricePerShare" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TemporaryEquitySharesIssued" xlink:label="TemporaryEquitySharesIssued" xlink:title="TemporaryEquitySharesIssued" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="TemporaryEquityLineItems" xlink:to="TemporaryEquitySharesIssued" xlink:title="definition: TemporaryEquityLineItems to TemporaryEquitySharesIssued" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_TemporaryEquityConversionPricePerShare" xlink:label="TemporaryEquityConversionPricePerShare" xlink:title="TemporaryEquityConversionPricePerShare" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="TemporaryEquityLineItems" xlink:to="TemporaryEquityConversionPricePerShare" xlink:title="definition: TemporaryEquityLineItems to TemporaryEquityConversionPricePerShare" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInTemporaryEquityRollForward" xlink:label="IncreaseDecreaseInTemporaryEquityRollForward" xlink:title="IncreaseDecreaseInTemporaryEquityRollForward" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="TemporaryEquityLineItems" xlink:to="IncreaseDecreaseInTemporaryEquityRollForward" xlink:title="definition: TemporaryEquityLineItems to IncreaseDecreaseInTemporaryEquityRollForward" use="optional" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TemporaryEquityCarryingAmountAttributableToParent" xlink:label="TemporaryEquityCarryingAmountAttributableToParent" xlink:title="TemporaryEquityCarryingAmountAttributableToParent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncreaseDecreaseInTemporaryEquityRollForward" xlink:to="TemporaryEquityCarryingAmountAttributableToParent" xlink:title="definition: IncreaseDecreaseInTemporaryEquityRollForward to TemporaryEquityCarryingAmountAttributableToParent" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TemporaryEquityAccretionToRedemptionValue" xlink:label="TemporaryEquityAccretionToRedemptionValue" xlink:title="TemporaryEquityAccretionToRedemptionValue" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncreaseDecreaseInTemporaryEquityRollForward" xlink:to="TemporaryEquityAccretionToRedemptionValue" xlink:title="definition: IncreaseDecreaseInTemporaryEquityRollForward to TemporaryEquityAccretionToRedemptionValue" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_TemporaryEquityConversionOfConvertibleSecurities" xlink:label="TemporaryEquityConversionOfConvertibleSecurities" xlink:title="TemporaryEquityConversionOfConvertibleSecurities" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncreaseDecreaseInTemporaryEquityRollForward" xlink:to="TemporaryEquityConversionOfConvertibleSecurities" xlink:title="definition: IncreaseDecreaseInTemporaryEquityRollForward to TemporaryEquityConversionOfConvertibleSecurities" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ConversionOfStockSharesIssued1" xlink:label="ConversionOfStockSharesIssued1" xlink:title="ConversionOfStockSharesIssued1" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncreaseDecreaseInTemporaryEquityRollForward" xlink:to="ConversionOfStockSharesIssued1" xlink:title="definition: IncreaseDecreaseInTemporaryEquityRollForward to ConversionOfStockSharesIssued1" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TemporaryEquityStockIssuedDuringPeriodValueNewIssues" xlink:label="TemporaryEquityStockIssuedDuringPeriodValueNewIssues" xlink:title="TemporaryEquityStockIssuedDuringPeriodValueNewIssues" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncreaseDecreaseInTemporaryEquityRollForward" xlink:to="TemporaryEquityStockIssuedDuringPeriodValueNewIssues" xlink:title="definition: IncreaseDecreaseInTemporaryEquityRollForward to TemporaryEquityStockIssuedDuringPeriodValueNewIssues" use="optional" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromConvertibleDebt" xlink:label="ProceedsFromConvertibleDebt" xlink:title="ProceedsFromConvertibleDebt" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="TemporaryEquityLineItems" xlink:to="ProceedsFromConvertibleDebt" xlink:title="definition: TemporaryEquityLineItems to ProceedsFromConvertibleDebt" use="optional" order="6.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtConversionConvertedInstrumentSharesIssued1" xlink:label="DebtConversionConvertedInstrumentSharesIssued1" xlink:title="DebtConversionConvertedInstrumentSharesIssued1" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="TemporaryEquityLineItems" xlink:to="DebtConversionConvertedInstrumentSharesIssued1" xlink:title="definition: TemporaryEquityLineItems to DebtConversionConvertedInstrumentSharesIssued1" use="optional" order="7.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.2u.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails7">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="SubsequentEventTypeAxis" xlink:title="SubsequentEventTypeAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="SubsequentEventTypeDomain" xlink:title="SubsequentEventTypeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="SubsequentEventTypeAxis" xlink:to="SubsequentEventTypeDomain" xlink:title="definition: SubsequentEventTypeAxis to SubsequentEventTypeDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="SubsequentEventTypeDomain_2" xlink:title="SubsequentEventTypeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="SubsequentEventTypeAxis" xlink:to="SubsequentEventTypeDomain_2" xlink:title="definition: SubsequentEventTypeAxis to SubsequentEventTypeDomain" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SubsequentEventMember" xlink:label="SubsequentEventMember" xlink:title="SubsequentEventMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SubsequentEventTypeDomain" xlink:to="SubsequentEventMember" xlink:title="definition: SubsequentEventTypeDomain to SubsequentEventMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_AccountingPoliciesLineItems" xlink:label="AccountingPoliciesLineItems" xlink:title="AccountingPoliciesLineItems" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_AccountingPoliciesTable" xlink:label="AccountingPoliciesTable" xlink:title="AccountingPoliciesTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="AccountingPoliciesLineItems" xlink:to="AccountingPoliciesTable" xlink:title="definition: AccountingPoliciesLineItems to AccountingPoliciesTable" use="optional" order="1.0" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="AccountingPoliciesTable" xlink:to="SubsequentEventTypeAxis" xlink:title="definition: AccountingPoliciesTable to SubsequentEventTypeAxis" use="optional" order="1.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.2u.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails5">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:title="ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" use="optional" order="1.0" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PlanNameAxis" xlink:label="PlanNameAxis" xlink:title="PlanNameAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="PlanNameAxis" xlink:title="definition: ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable to PlanNameAxis" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="PlanNameDomain" xlink:title="PlanNameDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="PlanNameAxis" xlink:to="PlanNameDomain" xlink:title="definition: PlanNameAxis to PlanNameDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_EquityIncentivePlan2014Member" xlink:label="EquityIncentivePlan2014Member" xlink:title="EquityIncentivePlan2014Member" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="PlanNameDomain" xlink:to="EquityIncentivePlan2014Member" xlink:title="definition: PlanNameDomain to EquityIncentivePlan2014Member" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="AwardTypeAxis" xlink:title="AwardTypeAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="AwardTypeAxis" xlink:title="definition: ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable to AwardTypeAxis" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:title="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="AwardTypeAxis" xlink:to="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:title="definition: AwardTypeAxis to ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="RestrictedStockUnitsRSUMember" xlink:title="RestrictedStockUnitsRSUMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="RestrictedStockUnitsRSUMember" xlink:title="definition: ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain to RestrictedStockUnitsRSUMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" use="optional" order="2.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.2u.com/role/DisclosureSummaryOfSignificantAccountingPoliciesDetails2">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeAxis" xlink:label="RangeAxis" xlink:title="RangeAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeMember" xlink:label="RangeMember" xlink:title="RangeMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="RangeAxis" xlink:to="RangeMember" xlink:title="definition: RangeAxis to RangeMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeMember" xlink:label="RangeMember_2" xlink:title="RangeMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="RangeAxis" xlink:to="RangeMember_2" xlink:title="definition: RangeAxis to RangeMember" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MinimumMember" xlink:label="MinimumMember" xlink:title="MinimumMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="RangeMember" xlink:to="MinimumMember" xlink:title="definition: RangeMember to MinimumMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MaximumMember" xlink:label="MaximumMember" xlink:title="MaximumMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="RangeMember" xlink:to="MaximumMember" xlink:title="definition: RangeMember to MaximumMember" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_RevenueRecognitionLineItems" xlink:label="RevenueRecognitionLineItems" xlink:title="RevenueRecognitionLineItems" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_RevenueRecognitionTable" xlink:label="RevenueRecognitionTable" xlink:title="RevenueRecognitionTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="RevenueRecognitionLineItems" xlink:to="RevenueRecognitionTable" xlink:title="definition: RevenueRecognitionLineItems to RevenueRecognitionTable" use="optional" order="1.0" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="RevenueRecognitionTable" xlink:to="RangeAxis" xlink:title="definition: RevenueRecognitionTable to RangeAxis" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_PeriodToDeriveRevenueUnderLongTermContracts" xlink:label="PeriodToDeriveRevenueUnderLongTermContracts" xlink:title="PeriodToDeriveRevenueUnderLongTermContracts" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="RevenueRecognitionLineItems" xlink:to="PeriodToDeriveRevenueUnderLongTermContracts" xlink:title="definition: RevenueRecognitionLineItems to PeriodToDeriveRevenueUnderLongTermContracts" use="optional" order="2.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.2u.com/role/DisclosureNetLossPerShareDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="AwardTypeAxis" xlink:title="AwardTypeAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:title="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="AwardTypeAxis" xlink:to="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:title="definition: AwardTypeAxis to ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:label="RestrictedStockUnitsRSUMember" xlink:title="RestrictedStockUnitsRSUMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="RestrictedStockUnitsRSUMember" xlink:title="definition: ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain to RestrictedStockUnitsRSUMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:label="AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:title="AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:label="ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:title="ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:to="ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:title="definition: AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems to ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" use="optional" order="1.0" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:label="AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:title="AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:to="AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:title="definition: ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable to AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AntidilutiveSecuritiesNameDomain" xlink:label="AntidilutiveSecuritiesNameDomain" xlink:title="AntidilutiveSecuritiesNameDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:to="AntidilutiveSecuritiesNameDomain" xlink:title="definition: AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis to AntidilutiveSecuritiesNameDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AntidilutiveSecuritiesNameDomain" xlink:label="AntidilutiveSecuritiesNameDomain_2" xlink:title="AntidilutiveSecuritiesNameDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:to="AntidilutiveSecuritiesNameDomain_2" xlink:title="definition: AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis to AntidilutiveSecuritiesNameDomain" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_RedeemableConvertibleSeriesAPreferredStockMember" xlink:label="RedeemableConvertibleSeriesAPreferredStockMember" xlink:title="RedeemableConvertibleSeriesAPreferredStockMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="AntidilutiveSecuritiesNameDomain" xlink:to="RedeemableConvertibleSeriesAPreferredStockMember" xlink:title="definition: AntidilutiveSecuritiesNameDomain to RedeemableConvertibleSeriesAPreferredStockMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_RedeemableConvertibleSeriesBPreferredStockMember" xlink:label="RedeemableConvertibleSeriesBPreferredStockMember" xlink:title="RedeemableConvertibleSeriesBPreferredStockMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="AntidilutiveSecuritiesNameDomain" xlink:to="RedeemableConvertibleSeriesBPreferredStockMember" xlink:title="definition: AntidilutiveSecuritiesNameDomain to RedeemableConvertibleSeriesBPreferredStockMember" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_RedeemableConvertibleSeriesCPreferredStockMember" xlink:label="RedeemableConvertibleSeriesCPreferredStockMember" xlink:title="RedeemableConvertibleSeriesCPreferredStockMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="AntidilutiveSecuritiesNameDomain" xlink:to="RedeemableConvertibleSeriesCPreferredStockMember" xlink:title="definition: AntidilutiveSecuritiesNameDomain to RedeemableConvertibleSeriesCPreferredStockMember" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_RedeemableConvertibleSeriesDPreferredStockMember" xlink:label="RedeemableConvertibleSeriesDPreferredStockMember" xlink:title="RedeemableConvertibleSeriesDPreferredStockMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="AntidilutiveSecuritiesNameDomain" xlink:to="RedeemableConvertibleSeriesDPreferredStockMember" xlink:title="definition: AntidilutiveSecuritiesNameDomain to RedeemableConvertibleSeriesDPreferredStockMember" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_WarrantsToPurchaseSeriesDRedeemableConvertiblePreferredStockMember" xlink:label="WarrantsToPurchaseSeriesDRedeemableConvertiblePreferredStockMember" xlink:title="WarrantsToPurchaseSeriesDRedeemableConvertiblePreferredStockMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="AntidilutiveSecuritiesNameDomain" xlink:to="WarrantsToPurchaseSeriesDRedeemableConvertiblePreferredStockMember" xlink:title="definition: AntidilutiveSecuritiesNameDomain to WarrantsToPurchaseSeriesDRedeemableConvertiblePreferredStockMember" use="optional" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="EmployeeStockOptionMember" xlink:title="EmployeeStockOptionMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="AntidilutiveSecuritiesNameDomain" xlink:to="EmployeeStockOptionMember" xlink:title="definition: AntidilutiveSecuritiesNameDomain to EmployeeStockOptionMember" use="optional" order="6.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_WarrantsToPurchaseSeriesCRedeemableConvertiblePreferredStockMember" xlink:label="WarrantsToPurchaseSeriesCRedeemableConvertiblePreferredStockMember" xlink:title="WarrantsToPurchaseSeriesCRedeemableConvertiblePreferredStockMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="AntidilutiveSecuritiesNameDomain" xlink:to="WarrantsToPurchaseSeriesCRedeemableConvertiblePreferredStockMember" xlink:title="definition: AntidilutiveSecuritiesNameDomain to WarrantsToPurchaseSeriesCRedeemableConvertiblePreferredStockMember" use="optional" order="7.0" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable" xlink:to="AwardTypeAxis" xlink:title="definition: ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable to AwardTypeAxis" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:label="AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:title="AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems" xlink:to="AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" xlink:title="definition: AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems to AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount" use="optional" order="2.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.2u.com/role/DisclosureSubsequentEventsDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="SubsequentEventTypeAxis" xlink:title="SubsequentEventTypeAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="SubsequentEventTypeDomain" xlink:title="SubsequentEventTypeDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="SubsequentEventTypeAxis" xlink:to="SubsequentEventTypeDomain" xlink:title="definition: SubsequentEventTypeAxis to SubsequentEventTypeDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SubsequentEventMember" xlink:label="SubsequentEventMember" xlink:title="SubsequentEventMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SubsequentEventTypeDomain" xlink:to="SubsequentEventMember" xlink:title="definition: SubsequentEventTypeDomain to SubsequentEventMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SubsequentEventLineItems" xlink:label="SubsequentEventLineItems" xlink:title="SubsequentEventLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SubsequentEventTable" xlink:label="SubsequentEventTable" xlink:title="SubsequentEventTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="SubsequentEventLineItems" xlink:to="SubsequentEventTable" xlink:title="definition: SubsequentEventLineItems to SubsequentEventTable" use="optional" order="1.0" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="SubsequentEventTable" xlink:to="SubsequentEventTypeAxis" xlink:title="definition: SubsequentEventTable to SubsequentEventTypeAxis" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_CommonStockSoldBySellingStockholders" xlink:label="CommonStockSoldBySellingStockholders" xlink:title="CommonStockSoldBySellingStockholders" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SubsequentEventLineItems" xlink:to="CommonStockSoldBySellingStockholders" xlink:title="definition: SubsequentEventLineItems to CommonStockSoldBySellingStockholders" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_GrossProceedsFromIssuanceInitialPublicOffering" xlink:label="GrossProceedsFromIssuanceInitialPublicOffering" xlink:title="GrossProceedsFromIssuanceInitialPublicOffering" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SubsequentEventLineItems" xlink:to="GrossProceedsFromIssuanceInitialPublicOffering" xlink:title="definition: SubsequentEventLineItems to GrossProceedsFromIssuanceInitialPublicOffering" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_OfferingCostsOfInitialPublicOffering" xlink:label="OfferingCostsOfInitialPublicOffering" xlink:title="OfferingCostsOfInitialPublicOffering" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SubsequentEventLineItems" xlink:to="OfferingCostsOfInitialPublicOffering" xlink:title="definition: SubsequentEventLineItems to OfferingCostsOfInitialPublicOffering" use="optional" order="4.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.2u.com/role/DisclosureStockBasedCompensationDetail2">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeAxis" xlink:label="RangeAxis" xlink:title="RangeAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeMember" xlink:label="RangeMember" xlink:title="RangeMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="RangeAxis" xlink:to="RangeMember" xlink:title="definition: RangeAxis to RangeMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MaximumMember" xlink:label="MaximumMember" xlink:title="MaximumMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="RangeMember" xlink:to="MaximumMember" xlink:title="definition: RangeMember to MaximumMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:title="ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" use="optional" order="1.0" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PlanNameAxis" xlink:label="PlanNameAxis" xlink:title="PlanNameAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="PlanNameAxis" xlink:title="definition: ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable to PlanNameAxis" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="PlanNameDomain" xlink:title="PlanNameDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="PlanNameAxis" xlink:to="PlanNameDomain" xlink:title="definition: PlanNameAxis to PlanNameDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="PlanNameDomain_2" xlink:title="PlanNameDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="PlanNameAxis" xlink:to="PlanNameDomain_2" xlink:title="definition: PlanNameAxis to PlanNameDomain" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_EquityIncentivePlan2014Member" xlink:label="EquityIncentivePlan2014Member" xlink:title="EquityIncentivePlan2014Member" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="PlanNameDomain" xlink:to="EquityIncentivePlan2014Member" xlink:title="definition: PlanNameDomain to EquityIncentivePlan2014Member" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="AwardTypeAxis" xlink:title="AwardTypeAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="AwardTypeAxis" xlink:title="definition: ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable to AwardTypeAxis" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:title="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="AwardTypeAxis" xlink:to="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:title="definition: AwardTypeAxis to ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_2" xlink:title="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="AwardTypeAxis" xlink:to="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_2" xlink:title="definition: AwardTypeAxis to ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="EmployeeStockOptionMember" xlink:title="EmployeeStockOptionMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="EmployeeStockOptionMember" xlink:title="definition: ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain to EmployeeStockOptionMember" use="optional" order="1.0" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="RangeAxis" xlink:title="definition: ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable to RangeAxis" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_ShareBasedCompensationArrangementByShareBasedPaymentAwardPeriodOfAnnualAutomaticIncreaseInSharesAuthorized" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardPeriodOfAnnualAutomaticIncreaseInSharesAuthorized" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardPeriodOfAnnualAutomaticIncreaseInSharesAuthorized" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="ShareBasedCompensationArrangementByShareBasedPaymentAwardPeriodOfAnnualAutomaticIncreaseInSharesAuthorized" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to ShareBasedCompensationArrangementByShareBasedPaymentAwardPeriodOfAnnualAutomaticIncreaseInSharesAuthorized" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageAppliedOnOutstandingSharesOfCommonStockForAutomaticInclusionInPlan" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageAppliedOnOutstandingSharesOfCommonStockForAutomaticInclusionInPlan" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageAppliedOnOutstandingSharesOfCommonStockForAutomaticInclusionInPlan" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageAppliedOnOutstandingSharesOfCommonStockForAutomaticInclusionInPlan" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageAppliedOnOutstandingSharesOfCommonStockForAutomaticInclusionInPlan" use="optional" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" use="optional" order="6.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:to="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward to ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:title="StockIssuedDuringPeriodSharesStockOptionsExercised" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:to="StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward to StockIssuedDuringPeriodSharesStockOptionsExercised" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:to="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward to ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:to="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward to ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:to="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward to ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" use="optional" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:to="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward to ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber" use="optional" order="6.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward" xlink:to="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward to ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod" use="optional" order="7.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" use="optional" order="7.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:label="ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:title="ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:to="ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward to ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:label="ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:title="ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:to="ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward to ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" xlink:label="ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" xlink:title="ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:to="ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward to ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:to="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward to ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:to="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward to ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" use="optional" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:to="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward to ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageExercisePrice" use="optional" order="6.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice" xlink:label="ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice" xlink:title="ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward" xlink:to="ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward to ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice" use="optional" order="7.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" xlink:label="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" xlink:title="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" use="optional" order="8.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsGrantsInPeriodWeightedAverageRemainingContractualTerm" xlink:label="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsGrantsInPeriodWeightedAverageRemainingContractualTerm" xlink:title="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsGrantsInPeriodWeightedAverageRemainingContractualTerm" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" xlink:to="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsGrantsInPeriodWeightedAverageRemainingContractualTerm" xlink:title="definition: SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract to SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsGrantsInPeriodWeightedAverageRemainingContractualTerm" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisesInPeriodWeightedAverageRemainingContractualTerm" xlink:label="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisesInPeriodWeightedAverageRemainingContractualTerm" xlink:title="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisesInPeriodWeightedAverageRemainingContractualTerm" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" xlink:to="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisesInPeriodWeightedAverageRemainingContractualTerm" xlink:title="definition: SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract to SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisesInPeriodWeightedAverageRemainingContractualTerm" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:label="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:title="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" xlink:to="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:title="definition: SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract to SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:label="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:title="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" xlink:to="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:title="definition: SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract to SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1" xlink:label="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1" xlink:title="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract" xlink:to="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1" xlink:title="definition: SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsWeightedAverageRemainingContractualTermAbstract to SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingWeightedAverageRemainingContractualTerm1" use="optional" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsIntrinsicValueAbstract" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsIntrinsicValueAbstract" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsIntrinsicValueAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsIntrinsicValueAbstract" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsIntrinsicValueAbstract" use="optional" order="9.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsIntrinsicValueAbstract" xlink:to="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsIntrinsicValueAbstract to ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" xlink:label="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" xlink:title="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsIntrinsicValueAbstract" xlink:to="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsIntrinsicValueAbstract to SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsIntrinsicValueAbstract" xlink:to="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsIntrinsicValueAbstract to ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingAggregateIntrinsicValue" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems to ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" use="optional" order="10.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:label="EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:title="EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:to="EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract to EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:title="EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:to="EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract to EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" xlink:label="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" xlink:title="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract" xlink:to="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" xlink:title="definition: ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsAdditionalDisclosuresAbstract to ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" use="optional" order="3.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.2u.com/role/DisclosureNetLossPerShareTables">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="StatementLineItems" xlink:title="StatementLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable" xlink:label="ScheduleOfEarningsPerShareBasicByCommonClassTable" xlink:title="ScheduleOfEarningsPerShareBasicByCommonClassTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="StatementLineItems" xlink:to="ScheduleOfEarningsPerShareBasicByCommonClassTable" xlink:title="definition: StatementLineItems to ScheduleOfEarningsPerShareBasicByCommonClassTable" use="optional" order="1.0" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="StatementScenarioAxis" xlink:title="StatementScenarioAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfEarningsPerShareBasicByCommonClassTable" xlink:to="StatementScenarioAxis" xlink:title="definition: ScheduleOfEarningsPerShareBasicByCommonClassTable to StatementScenarioAxis" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="ScenarioUnspecifiedDomain" xlink:title="ScenarioUnspecifiedDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="StatementScenarioAxis" xlink:to="ScenarioUnspecifiedDomain" xlink:title="definition: StatementScenarioAxis to ScenarioUnspecifiedDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="ScenarioUnspecifiedDomain_2" xlink:title="ScenarioUnspecifiedDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="StatementScenarioAxis" xlink:to="ScenarioUnspecifiedDomain_2" xlink:title="definition: StatementScenarioAxis to ScenarioUnspecifiedDomain" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProFormaMember" xlink:label="ProFormaMember" xlink:title="ProFormaMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ScenarioUnspecifiedDomain" xlink:to="ProFormaMember" xlink:title="definition: ScenarioUnspecifiedDomain to ProFormaMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock" xlink:label="ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock" xlink:title="ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock" xlink:title="definition: StatementLineItems to ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" xlink:label="ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" xlink:title="ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" xlink:title="definition: StatementLineItems to ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock" use="optional" order="3.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.2u.com/role/DisclosureStockBasedCompensationDetails">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems" xlink:label="EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems" xlink:title="EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" xlink:label="ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" xlink:title="ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems" xlink:to="ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" xlink:title="definition: EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems to ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" use="optional" order="1.0" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="IncomeStatementLocationAxis" xlink:title="IncomeStatementLocationAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable" xlink:to="IncomeStatementLocationAxis" xlink:title="definition: ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTable to IncomeStatementLocationAxis" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="IncomeStatementLocationDomain" xlink:title="IncomeStatementLocationDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="IncomeStatementLocationAxis" xlink:to="IncomeStatementLocationDomain" xlink:title="definition: IncomeStatementLocationAxis to IncomeStatementLocationDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="IncomeStatementLocationDomain_2" xlink:title="IncomeStatementLocationDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="IncomeStatementLocationAxis" xlink:to="IncomeStatementLocationDomain_2" xlink:title="definition: IncomeStatementLocationAxis to IncomeStatementLocationDomain" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_ServicingAndSupportMember" xlink:label="ServicingAndSupportMember" xlink:title="ServicingAndSupportMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncomeStatementLocationDomain" xlink:to="ServicingAndSupportMember" xlink:title="definition: IncomeStatementLocationDomain to ServicingAndSupportMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_TechnologyAndContentDevelopmentMember" xlink:label="TechnologyAndContentDevelopmentMember" xlink:title="TechnologyAndContentDevelopmentMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncomeStatementLocationDomain" xlink:to="TechnologyAndContentDevelopmentMember" xlink:title="definition: IncomeStatementLocationDomain to TechnologyAndContentDevelopmentMember" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SellingAndMarketingExpenseMember" xlink:label="SellingAndMarketingExpenseMember" xlink:title="SellingAndMarketingExpenseMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncomeStatementLocationDomain" xlink:to="SellingAndMarketingExpenseMember" xlink:title="definition: IncomeStatementLocationDomain to SellingAndMarketingExpenseMember" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_GeneralAndAdministrativeExpenseMember" xlink:label="GeneralAndAdministrativeExpenseMember" xlink:title="GeneralAndAdministrativeExpenseMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncomeStatementLocationDomain" xlink:to="GeneralAndAdministrativeExpenseMember" xlink:title="definition: IncomeStatementLocationDomain to GeneralAndAdministrativeExpenseMember" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="AllocatedShareBasedCompensationExpense" xlink:title="AllocatedShareBasedCompensationExpense" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems" xlink:to="AllocatedShareBasedCompensationExpense" xlink:title="definition: EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems to AllocatedShareBasedCompensationExpense" use="optional" order="2.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.2u.com/role/BalanceSheetParenthetical">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="StatementClassOfStockAxis" xlink:title="StatementClassOfStockAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="ClassOfStockDomain" xlink:title="ClassOfStockDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="StatementClassOfStockAxis" xlink:to="ClassOfStockDomain" xlink:title="definition: StatementClassOfStockAxis to ClassOfStockDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_RedeemableConvertibleSeriesCPreferredStockMember" xlink:label="RedeemableConvertibleSeriesCPreferredStockMember" xlink:title="RedeemableConvertibleSeriesCPreferredStockMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfStockDomain" xlink:to="RedeemableConvertibleSeriesCPreferredStockMember" xlink:title="definition: ClassOfStockDomain to RedeemableConvertibleSeriesCPreferredStockMember" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_RedeemableConvertibleSeriesAPreferredStockMember" xlink:label="RedeemableConvertibleSeriesAPreferredStockMember" xlink:title="RedeemableConvertibleSeriesAPreferredStockMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfStockDomain" xlink:to="RedeemableConvertibleSeriesAPreferredStockMember" xlink:title="definition: ClassOfStockDomain to RedeemableConvertibleSeriesAPreferredStockMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_RedeemableConvertibleSeriesBPreferredStockMember" xlink:label="RedeemableConvertibleSeriesBPreferredStockMember" xlink:title="RedeemableConvertibleSeriesBPreferredStockMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfStockDomain" xlink:to="RedeemableConvertibleSeriesBPreferredStockMember" xlink:title="definition: ClassOfStockDomain to RedeemableConvertibleSeriesBPreferredStockMember" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_RedeemableConvertibleSeriesDPreferredStockMember" xlink:label="RedeemableConvertibleSeriesDPreferredStockMember" xlink:title="RedeemableConvertibleSeriesDPreferredStockMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfStockDomain" xlink:to="RedeemableConvertibleSeriesDPreferredStockMember" xlink:title="definition: ClassOfStockDomain to RedeemableConvertibleSeriesDPreferredStockMember" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="StatementScenarioAxis" xlink:title="StatementScenarioAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="ScenarioUnspecifiedDomain" xlink:title="ScenarioUnspecifiedDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="StatementScenarioAxis" xlink:to="ScenarioUnspecifiedDomain" xlink:title="definition: StatementScenarioAxis to ScenarioUnspecifiedDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProFormaMember" xlink:label="ProFormaMember" xlink:title="ProFormaMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ScenarioUnspecifiedDomain" xlink:to="ProFormaMember" xlink:title="definition: ScenarioUnspecifiedDomain to ProFormaMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="StatementLineItems" xlink:title="StatementLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:label="StatementTable" xlink:title="StatementTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="StatementLineItems" xlink:to="StatementTable" xlink:title="definition: StatementLineItems to StatementTable" use="optional" order="1.0" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="StatementTable" xlink:to="StatementClassOfStockAxis" xlink:title="definition: StatementTable to StatementClassOfStockAxis" use="optional" order="1.0" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="StatementTable" xlink:to="StatementScenarioAxis" xlink:title="definition: StatementTable to StatementScenarioAxis" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TemporaryEquityParOrStatedValuePerShare" xlink:label="TemporaryEquityParOrStatedValuePerShare" xlink:title="TemporaryEquityParOrStatedValuePerShare" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="TemporaryEquityParOrStatedValuePerShare" xlink:title="definition: StatementLineItems to TemporaryEquityParOrStatedValuePerShare" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TemporaryEquitySharesAuthorized" xlink:label="TemporaryEquitySharesAuthorized" xlink:title="TemporaryEquitySharesAuthorized" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="TemporaryEquitySharesAuthorized" xlink:title="definition: StatementLineItems to TemporaryEquitySharesAuthorized" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TemporaryEquitySharesIssued" xlink:label="TemporaryEquitySharesIssued" xlink:title="TemporaryEquitySharesIssued" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="TemporaryEquitySharesIssued" xlink:title="definition: StatementLineItems to TemporaryEquitySharesIssued" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TemporaryEquitySharesOutstanding" xlink:label="TemporaryEquitySharesOutstanding" xlink:title="TemporaryEquitySharesOutstanding" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="TemporaryEquitySharesOutstanding" xlink:title="definition: StatementLineItems to TemporaryEquitySharesOutstanding" use="optional" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockParOrStatedValuePerShare" xlink:label="PreferredStockParOrStatedValuePerShare" xlink:title="PreferredStockParOrStatedValuePerShare" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="PreferredStockParOrStatedValuePerShare" xlink:title="definition: StatementLineItems to PreferredStockParOrStatedValuePerShare" use="optional" order="6.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockSharesAuthorized" xlink:label="PreferredStockSharesAuthorized" xlink:title="PreferredStockSharesAuthorized" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="PreferredStockSharesAuthorized" xlink:title="definition: StatementLineItems to PreferredStockSharesAuthorized" use="optional" order="7.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockSharesIssued" xlink:label="PreferredStockSharesIssued" xlink:title="PreferredStockSharesIssued" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="PreferredStockSharesIssued" xlink:title="definition: StatementLineItems to PreferredStockSharesIssued" use="optional" order="8.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockSharesOutstanding" xlink:label="PreferredStockSharesOutstanding" xlink:title="PreferredStockSharesOutstanding" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="PreferredStockSharesOutstanding" xlink:title="definition: StatementLineItems to PreferredStockSharesOutstanding" use="optional" order="9.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="CommonStockParOrStatedValuePerShare" xlink:title="CommonStockParOrStatedValuePerShare" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="CommonStockParOrStatedValuePerShare" xlink:title="definition: StatementLineItems to CommonStockParOrStatedValuePerShare" use="optional" order="10.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="CommonStockSharesAuthorized" xlink:title="CommonStockSharesAuthorized" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="CommonStockSharesAuthorized" xlink:title="definition: StatementLineItems to CommonStockSharesAuthorized" use="optional" order="11.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockSharesIssued" xlink:label="CommonStockSharesIssued" xlink:title="CommonStockSharesIssued" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="CommonStockSharesIssued" xlink:title="definition: StatementLineItems to CommonStockSharesIssued" use="optional" order="12.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="CommonStockSharesOutstanding" xlink:title="CommonStockSharesOutstanding" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="CommonStockSharesOutstanding" xlink:title="definition: StatementLineItems to CommonStockSharesOutstanding" use="optional" order="13.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TemporaryEquityLiquidationPreference" xlink:label="TemporaryEquityLiquidationPreference" xlink:title="TemporaryEquityLiquidationPreference" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="TemporaryEquityLiquidationPreference" xlink:title="definition: StatementLineItems to TemporaryEquityLiquidationPreference" use="optional" order="14.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.2u.com/role/BalanceSheet">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="StatementClassOfStockAxis" xlink:title="StatementClassOfStockAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="ClassOfStockDomain" xlink:title="ClassOfStockDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="StatementClassOfStockAxis" xlink:to="ClassOfStockDomain" xlink:title="definition: StatementClassOfStockAxis to ClassOfStockDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="ClassOfStockDomain_2" xlink:title="ClassOfStockDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="StatementClassOfStockAxis" xlink:to="ClassOfStockDomain_2" xlink:title="definition: StatementClassOfStockAxis to ClassOfStockDomain" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_RedeemableConvertibleSeriesCPreferredStockMember" xlink:label="RedeemableConvertibleSeriesCPreferredStockMember" xlink:title="RedeemableConvertibleSeriesCPreferredStockMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfStockDomain" xlink:to="RedeemableConvertibleSeriesCPreferredStockMember" xlink:title="definition: ClassOfStockDomain to RedeemableConvertibleSeriesCPreferredStockMember" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_RedeemableConvertibleSeriesAPreferredStockMember" xlink:label="RedeemableConvertibleSeriesAPreferredStockMember" xlink:title="RedeemableConvertibleSeriesAPreferredStockMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfStockDomain" xlink:to="RedeemableConvertibleSeriesAPreferredStockMember" xlink:title="definition: ClassOfStockDomain to RedeemableConvertibleSeriesAPreferredStockMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_RedeemableConvertibleSeriesBPreferredStockMember" xlink:label="RedeemableConvertibleSeriesBPreferredStockMember" xlink:title="RedeemableConvertibleSeriesBPreferredStockMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfStockDomain" xlink:to="RedeemableConvertibleSeriesBPreferredStockMember" xlink:title="definition: ClassOfStockDomain to RedeemableConvertibleSeriesBPreferredStockMember" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_RedeemableConvertibleSeriesDPreferredStockMember" xlink:label="RedeemableConvertibleSeriesDPreferredStockMember" xlink:title="RedeemableConvertibleSeriesDPreferredStockMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ClassOfStockDomain" xlink:to="RedeemableConvertibleSeriesDPreferredStockMember" xlink:title="definition: ClassOfStockDomain to RedeemableConvertibleSeriesDPreferredStockMember" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="StatementScenarioAxis" xlink:title="StatementScenarioAxis" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="ScenarioUnspecifiedDomain" xlink:title="ScenarioUnspecifiedDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="StatementScenarioAxis" xlink:to="ScenarioUnspecifiedDomain" xlink:title="definition: StatementScenarioAxis to ScenarioUnspecifiedDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProFormaMember" xlink:label="ProFormaMember" xlink:title="ProFormaMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="ScenarioUnspecifiedDomain" xlink:to="ProFormaMember" xlink:title="definition: ScenarioUnspecifiedDomain to ProFormaMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="StatementLineItems" xlink:title="StatementLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:label="StatementTable" xlink:title="StatementTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="StatementLineItems" xlink:to="StatementTable" xlink:title="definition: StatementLineItems to StatementTable" use="optional" order="1.0" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="StatementTable" xlink:to="StatementClassOfStockAxis" xlink:title="definition: StatementTable to StatementClassOfStockAxis" use="optional" order="1.0" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="StatementTable" xlink:to="StatementScenarioAxis" xlink:title="definition: StatementTable to StatementScenarioAxis" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AssetsAbstract" xlink:label="AssetsAbstract" xlink:title="AssetsAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="AssetsAbstract" xlink:title="definition: StatementLineItems to AssetsAbstract" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AssetsCurrentAbstract" xlink:label="AssetsCurrentAbstract" xlink:title="AssetsCurrentAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="AssetsAbstract" xlink:to="AssetsCurrentAbstract" xlink:title="definition: AssetsAbstract to AssetsCurrentAbstract" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="CashAndCashEquivalentsAtCarryingValue" xlink:title="CashAndCashEquivalentsAtCarryingValue" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="AssetsCurrentAbstract" xlink:to="CashAndCashEquivalentsAtCarryingValue" xlink:title="definition: AssetsCurrentAbstract to CashAndCashEquivalentsAtCarryingValue" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="AccountsReceivableNetCurrent" xlink:title="AccountsReceivableNetCurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="AssetsCurrentAbstract" xlink:to="AccountsReceivableNetCurrent" xlink:title="definition: AssetsCurrentAbstract to AccountsReceivableNetCurrent" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_AdvanceToClientsCurrent" xlink:label="AdvanceToClientsCurrent" xlink:title="AdvanceToClientsCurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="AssetsCurrentAbstract" xlink:to="AdvanceToClientsCurrent" xlink:title="definition: AssetsCurrentAbstract to AdvanceToClientsCurrent" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PrepaidExpenseCurrent" xlink:label="PrepaidExpenseCurrent" xlink:title="PrepaidExpenseCurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="AssetsCurrentAbstract" xlink:to="PrepaidExpenseCurrent" xlink:title="definition: AssetsCurrentAbstract to PrepaidExpenseCurrent" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="AssetsCurrent" xlink:title="AssetsCurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="AssetsCurrentAbstract" xlink:to="AssetsCurrent" xlink:title="definition: AssetsCurrentAbstract to AssetsCurrent" use="optional" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="PropertyPlantAndEquipmentNet" xlink:title="PropertyPlantAndEquipmentNet" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="AssetsAbstract" xlink:to="PropertyPlantAndEquipmentNet" xlink:title="definition: AssetsAbstract to PropertyPlantAndEquipmentNet" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_CapitalizedContentDevelopmentCostsNet" xlink:label="CapitalizedContentDevelopmentCostsNet" xlink:title="CapitalizedContentDevelopmentCostsNet" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="AssetsAbstract" xlink:to="CapitalizedContentDevelopmentCostsNet" xlink:title="definition: AssetsAbstract to CapitalizedContentDevelopmentCostsNet" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_AdvanceToClientsNoncurrent" xlink:label="AdvanceToClientsNoncurrent" xlink:title="AdvanceToClientsNoncurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="AssetsAbstract" xlink:to="AdvanceToClientsNoncurrent" xlink:title="definition: AssetsAbstract to AdvanceToClientsNoncurrent" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="OtherAssetsNoncurrent" xlink:title="OtherAssetsNoncurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="AssetsAbstract" xlink:to="OtherAssetsNoncurrent" xlink:title="definition: AssetsAbstract to OtherAssetsNoncurrent" use="optional" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_Assets" xlink:label="Assets" xlink:title="Assets" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="AssetsAbstract" xlink:to="Assets" xlink:title="definition: AssetsAbstract to Assets" use="optional" order="6.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DueFromRelatedPartiesNoncurrent" xlink:label="DueFromRelatedPartiesNoncurrent" xlink:title="DueFromRelatedPartiesNoncurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="AssetsAbstract" xlink:to="DueFromRelatedPartiesNoncurrent" xlink:title="definition: AssetsAbstract to DueFromRelatedPartiesNoncurrent" use="optional" order="7.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:label="LiabilitiesAndStockholdersEquityAbstract" xlink:title="LiabilitiesAndStockholdersEquityAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="LiabilitiesAndStockholdersEquityAbstract" xlink:title="definition: StatementLineItems to LiabilitiesAndStockholdersEquityAbstract" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LiabilitiesCurrentAbstract" xlink:label="LiabilitiesCurrentAbstract" xlink:title="LiabilitiesCurrentAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LiabilitiesAndStockholdersEquityAbstract" xlink:to="LiabilitiesCurrentAbstract" xlink:title="definition: LiabilitiesAndStockholdersEquityAbstract to LiabilitiesCurrentAbstract" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:label="AccountsPayableCurrent" xlink:title="AccountsPayableCurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LiabilitiesCurrentAbstract" xlink:to="AccountsPayableCurrent" xlink:title="definition: LiabilitiesCurrentAbstract to AccountsPayableCurrent" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccruedLiabilitiesAndOtherLiabilities" xlink:label="AccruedLiabilitiesAndOtherLiabilities" xlink:title="AccruedLiabilitiesAndOtherLiabilities" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LiabilitiesCurrentAbstract" xlink:to="AccruedLiabilitiesAndOtherLiabilities" xlink:title="definition: LiabilitiesCurrentAbstract to AccruedLiabilitiesAndOtherLiabilities" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredRevenueCurrent" xlink:label="DeferredRevenueCurrent" xlink:title="DeferredRevenueCurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LiabilitiesCurrentAbstract" xlink:to="DeferredRevenueCurrent" xlink:title="definition: LiabilitiesCurrentAbstract to DeferredRevenueCurrent" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_RefundsPayableCurrent" xlink:label="RefundsPayableCurrent" xlink:title="RefundsPayableCurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LiabilitiesCurrentAbstract" xlink:to="RefundsPayableCurrent" xlink:title="definition: LiabilitiesCurrentAbstract to RefundsPayableCurrent" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="LiabilitiesCurrent" xlink:title="LiabilitiesCurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LiabilitiesCurrentAbstract" xlink:to="LiabilitiesCurrent" xlink:title="definition: LiabilitiesCurrentAbstract to LiabilitiesCurrent" use="optional" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_RebateReserveNoncurrent" xlink:label="RebateReserveNoncurrent" xlink:title="RebateReserveNoncurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LiabilitiesAndStockholdersEquityAbstract" xlink:to="RebateReserveNoncurrent" xlink:title="definition: LiabilitiesAndStockholdersEquityAbstract to RebateReserveNoncurrent" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:label="OtherLiabilitiesNoncurrent" xlink:title="OtherLiabilitiesNoncurrent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LiabilitiesAndStockholdersEquityAbstract" xlink:to="OtherLiabilitiesNoncurrent" xlink:title="definition: LiabilitiesAndStockholdersEquityAbstract to OtherLiabilitiesNoncurrent" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_Liabilities" xlink:label="Liabilities" xlink:title="Liabilities" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LiabilitiesAndStockholdersEquityAbstract" xlink:to="Liabilities" xlink:title="definition: LiabilitiesAndStockholdersEquityAbstract to Liabilities" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommitmentsAndContingencies" xlink:label="CommitmentsAndContingencies" xlink:title="CommitmentsAndContingencies" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LiabilitiesAndStockholdersEquityAbstract" xlink:to="CommitmentsAndContingencies" xlink:title="definition: LiabilitiesAndStockholdersEquityAbstract to CommitmentsAndContingencies" use="optional" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TemporaryEquityAbstract" xlink:label="TemporaryEquityAbstract" xlink:title="TemporaryEquityAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LiabilitiesAndStockholdersEquityAbstract" xlink:to="TemporaryEquityAbstract" xlink:title="definition: LiabilitiesAndStockholdersEquityAbstract to TemporaryEquityAbstract" use="optional" order="6.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TemporaryEquityCarryingAmountAttributableToParent" xlink:label="TemporaryEquityCarryingAmountAttributableToParent" xlink:title="TemporaryEquityCarryingAmountAttributableToParent" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="TemporaryEquityAbstract" xlink:to="TemporaryEquityCarryingAmountAttributableToParent" xlink:title="definition: TemporaryEquityAbstract to TemporaryEquityCarryingAmountAttributableToParent" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockholdersEquityAbstract" xlink:label="StockholdersEquityAbstract" xlink:title="StockholdersEquityAbstract" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="TemporaryEquityAbstract" xlink:to="StockholdersEquityAbstract" xlink:title="definition: TemporaryEquityAbstract to StockholdersEquityAbstract" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockValue" xlink:label="PreferredStockValue" xlink:title="PreferredStockValue" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StockholdersEquityAbstract" xlink:to="PreferredStockValue" xlink:title="definition: StockholdersEquityAbstract to PreferredStockValue" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockValue" xlink:label="CommonStockValue" xlink:title="CommonStockValue" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StockholdersEquityAbstract" xlink:to="CommonStockValue" xlink:title="definition: StockholdersEquityAbstract to CommonStockValue" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdditionalPaidInCapital" xlink:label="AdditionalPaidInCapital" xlink:title="AdditionalPaidInCapital" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StockholdersEquityAbstract" xlink:to="AdditionalPaidInCapital" xlink:title="definition: StockholdersEquityAbstract to AdditionalPaidInCapital" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="RetainedEarningsAccumulatedDeficit" xlink:title="RetainedEarningsAccumulatedDeficit" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StockholdersEquityAbstract" xlink:to="RetainedEarningsAccumulatedDeficit" xlink:title="definition: StockholdersEquityAbstract to RetainedEarningsAccumulatedDeficit" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="StockholdersEquity" xlink:title="StockholdersEquity" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StockholdersEquityAbstract" xlink:to="StockholdersEquity" xlink:title="definition: StockholdersEquityAbstract to StockholdersEquity" use="optional" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="LiabilitiesAndStockholdersEquity" xlink:title="LiabilitiesAndStockholdersEquity" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="LiabilitiesAndStockholdersEquityAbstract" xlink:to="LiabilitiesAndStockholdersEquity" xlink:title="definition: LiabilitiesAndStockholdersEquityAbstract to LiabilitiesAndStockholdersEquity" use="optional" order="7.0" />
  </link:definitionLink>
  <link:definitionLink xlink:type="extended" xlink:role="http://www.2u.com/role/StatementOfStockholdersEquity">
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:label="StatementLineItems" xlink:title="StatementLineItems" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:label="StatementTable" xlink:title="StatementTable" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="StatementLineItems" xlink:to="StatementTable" xlink:title="definition: StatementLineItems to StatementTable" use="optional" order="1.0" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="StatementEquityComponentsAxis" xlink:title="StatementEquityComponentsAxis" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="StatementTable" xlink:to="StatementEquityComponentsAxis" xlink:title="definition: StatementTable to StatementEquityComponentsAxis" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="EquityComponentDomain" xlink:title="EquityComponentDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="StatementEquityComponentsAxis" xlink:to="EquityComponentDomain" xlink:title="definition: StatementEquityComponentsAxis to EquityComponentDomain" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="EquityComponentDomain_2" xlink:title="EquityComponentDomain" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="StatementEquityComponentsAxis" xlink:to="EquityComponentDomain_2" xlink:title="definition: StatementEquityComponentsAxis to EquityComponentDomain" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockMember" xlink:label="CommonStockMember" xlink:title="CommonStockMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EquityComponentDomain" xlink:to="CommonStockMember" xlink:title="definition: EquityComponentDomain to CommonStockMember" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="AdditionalPaidInCapitalMember" xlink:title="AdditionalPaidInCapitalMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EquityComponentDomain" xlink:to="AdditionalPaidInCapitalMember" xlink:title="definition: EquityComponentDomain to AdditionalPaidInCapitalMember" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RetainedEarningsMember" xlink:label="RetainedEarningsMember" xlink:title="RetainedEarningsMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EquityComponentDomain" xlink:to="RetainedEarningsMember" xlink:title="definition: EquityComponentDomain to RetainedEarningsMember" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="AccumulatedOtherComprehensiveIncomeMember" xlink:title="AccumulatedOtherComprehensiveIncomeMember" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="EquityComponentDomain" xlink:to="AccumulatedOtherComprehensiveIncomeMember" xlink:title="definition: EquityComponentDomain to AccumulatedOtherComprehensiveIncomeMember" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward" xlink:label="IncreaseDecreaseInStockholdersEquityRollForward" xlink:title="IncreaseDecreaseInStockholdersEquityRollForward" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StatementLineItems" xlink:to="IncreaseDecreaseInStockholdersEquityRollForward" xlink:title="definition: StatementLineItems to IncreaseDecreaseInStockholdersEquityRollForward" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="StockholdersEquity" xlink:title="StockholdersEquity" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="StockholdersEquity" xlink:title="definition: IncreaseDecreaseInStockholdersEquityRollForward to StockholdersEquity" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="CommonStockSharesOutstanding" xlink:title="CommonStockSharesOutstanding" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="CommonStockSharesOutstanding" xlink:title="definition: IncreaseDecreaseInStockholdersEquityRollForward to CommonStockSharesOutstanding" use="optional" order="2.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:label="StockIssuedDuringPeriodValueStockOptionsExercised" xlink:title="StockIssuedDuringPeriodValueStockOptionsExercised" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="StockIssuedDuringPeriodValueStockOptionsExercised" xlink:title="definition: IncreaseDecreaseInStockholdersEquityRollForward to StockIssuedDuringPeriodValueStockOptionsExercised" use="optional" order="3.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:label="StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:title="StockIssuedDuringPeriodSharesStockOptionsExercised" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StockIssuedDuringPeriodValueStockOptionsExercised" xlink:to="StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:title="definition: StockIssuedDuringPeriodValueStockOptionsExercised to StockIssuedDuringPeriodSharesStockOptionsExercised" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation" xlink:label="StockIssuedDuringPeriodValueShareBasedCompensation" xlink:title="StockIssuedDuringPeriodValueShareBasedCompensation" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="StockIssuedDuringPeriodValueShareBasedCompensation" xlink:title="definition: IncreaseDecreaseInStockholdersEquityRollForward to StockIssuedDuringPeriodValueShareBasedCompensation" use="optional" order="4.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:label="StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:title="StockIssuedDuringPeriodSharesShareBasedCompensation" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StockIssuedDuringPeriodValueShareBasedCompensation" xlink:to="StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:title="definition: StockIssuedDuringPeriodValueShareBasedCompensation to StockIssuedDuringPeriodSharesShareBasedCompensation" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherPreferredStockDividendsAndAdjustments" xlink:label="OtherPreferredStockDividendsAndAdjustments" xlink:title="OtherPreferredStockDividendsAndAdjustments" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="OtherPreferredStockDividendsAndAdjustments" xlink:title="definition: IncreaseDecreaseInStockholdersEquityRollForward to OtherPreferredStockDividendsAndAdjustments" use="optional" order="5.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:label="AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:title="AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:title="definition: IncreaseDecreaseInStockholdersEquityRollForward to AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" use="optional" order="6.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueConversionOfConvertibleSecurities" xlink:label="StockIssuedDuringPeriodValueConversionOfConvertibleSecurities" xlink:title="StockIssuedDuringPeriodValueConversionOfConvertibleSecurities" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="StockIssuedDuringPeriodValueConversionOfConvertibleSecurities" xlink:title="definition: IncreaseDecreaseInStockholdersEquityRollForward to StockIssuedDuringPeriodValueConversionOfConvertibleSecurities" use="optional" order="7.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" xlink:label="StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" xlink:title="StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StockIssuedDuringPeriodValueConversionOfConvertibleSecurities" xlink:to="StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" xlink:title="definition: StockIssuedDuringPeriodValueConversionOfConvertibleSecurities to StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_AdjustmentsToAdditionalPaidInCapitalConversionOfWarrants" xlink:label="AdjustmentsToAdditionalPaidInCapitalConversionOfWarrants" xlink:title="AdjustmentsToAdditionalPaidInCapitalConversionOfWarrants" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="AdjustmentsToAdditionalPaidInCapitalConversionOfWarrants" xlink:title="definition: IncreaseDecreaseInStockholdersEquityRollForward to AdjustmentsToAdditionalPaidInCapitalConversionOfWarrants" use="optional" order="8.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:label="StockIssuedDuringPeriodValueNewIssues" xlink:title="StockIssuedDuringPeriodValueNewIssues" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="StockIssuedDuringPeriodValueNewIssues" xlink:title="definition: IncreaseDecreaseInStockholdersEquityRollForward to StockIssuedDuringPeriodValueNewIssues" use="optional" order="9.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:label="StockIssuedDuringPeriodSharesNewIssues" xlink:title="StockIssuedDuringPeriodSharesNewIssues" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StockIssuedDuringPeriodValueNewIssues" xlink:to="StockIssuedDuringPeriodSharesNewIssues" xlink:title="definition: StockIssuedDuringPeriodValueNewIssues to StockIssuedDuringPeriodSharesNewIssues" use="optional" order="1.0" />
    <link:loc xlink:type="locator" xlink:href="twou-20140630.xsd#twou_StockIssuedDuringPeriodSharesExerciseOfWarrantsToPurchaseCommonStock" xlink:label="StockIssuedDuringPeriodSharesExerciseOfWarrantsToPurchaseCommonStock" xlink:title="StockIssuedDuringPeriodSharesExerciseOfWarrantsToPurchaseCommonStock" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="StockIssuedDuringPeriodSharesExerciseOfWarrantsToPurchaseCommonStock" xlink:title="definition: IncreaseDecreaseInStockholdersEquityRollForward to StockIssuedDuringPeriodSharesExerciseOfWarrantsToPurchaseCommonStock" use="optional" order="10.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="NetIncomeLoss" xlink:title="NetIncomeLoss" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="NetIncomeLoss" xlink:title="definition: IncreaseDecreaseInStockholdersEquityRollForward to NetIncomeLoss" use="optional" order="11.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodValue" xlink:label="StockRepurchasedDuringPeriodValue" xlink:title="StockRepurchasedDuringPeriodValue" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="IncreaseDecreaseInStockholdersEquityRollForward" xlink:to="StockRepurchasedDuringPeriodValue" xlink:title="definition: IncreaseDecreaseInStockholdersEquityRollForward to StockRepurchasedDuringPeriodValue" use="optional" order="12.0" />
    <link:loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockRepurchasedDuringPeriodShares" xlink:label="StockRepurchasedDuringPeriodShares" xlink:title="StockRepurchasedDuringPeriodShares" />
    <link:definitionArc xlink:type="arc" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="StockRepurchasedDuringPeriodValue" xlink:to="StockRepurchasedDuringPeriodShares" xlink:title="definition: StockRepurchasedDuringPeriodValue to StockRepurchasedDuringPeriodShares" use="optional" order="1.0" />
  </link:definitionLink>
</link:linkbase>


