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<!--Generated by DFIN XBRL Instance Document - http://www.dfinsolutions.com/ - Version R3.0 - on 16-April-2023 [02:42:22] {PM}-->
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<roleRef xlink:type="simple" xlink:href="http://www.xbrl.org/lrr/role/net-2009-12-16.xsd#netLabel" roleURI="http://www.xbrl.org/2009/role/netLabel" />
<labelLink xlink:type="extended" xlink:role="http://www.xbrl.org/2003/role/link">
<loc xlink:type="locator" xlink:href="exls-20221231.xsd#exls_DeductChangeInPensionValueMember" xlink:label="loc_exls_DeductChangeInPensionValueMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_exls_DeductChangeInPensionValueMember" xml:lang="en-US">Deduct change in pension value [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_exls_DeductChangeInPensionValueMember" xlink:to="lab_exls_DeductChangeInPensionValueMember" />
<loc xlink:type="locator" xlink:href="exls-20221231.xsd#exls_AddPensionServiceCostMember" xlink:label="loc_exls_AddPensionServiceCostMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_exls_AddPensionServiceCostMember" xml:lang="en-US">Add pension service cost [Member]</label>
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<loc xlink:type="locator" xlink:href="exls-20221231.xsd#exls_DeductStockAwardsMember" xlink:label="loc_exls_DeductStockAwardsMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_exls_DeductStockAwardsMember" xml:lang="en-US">Deduct stock awards [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_exls_DeductStockAwardsMember" xlink:to="lab_exls_DeductStockAwardsMember" />
<loc xlink:type="locator" xlink:href="exls-20221231.xsd#exls_AddChangeInValueOfEquityAwardsGrantedInPriorYearsWhichVestedInYearMember" xlink:label="loc_exls_AddChangeInValueOfEquityAwardsGrantedInPriorYearsWhichVestedInYearMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_exls_AddChangeInValueOfEquityAwardsGrantedInPriorYearsWhichVestedInYearMember" xml:lang="en-US">Add change in value of equity awards granted in prior years which vested in year [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_exls_AddChangeInValueOfEquityAwardsGrantedInPriorYearsWhichVestedInYearMember" xlink:to="lab_exls_AddChangeInValueOfEquityAwardsGrantedInPriorYearsWhichVestedInYearMember" />
<loc xlink:type="locator" xlink:href="exls-20221231.xsd#exls_AddYearendValueOfUnvestedEquityAwardsGrantedInYearMember" xlink:label="loc_exls_AddYearendValueOfUnvestedEquityAwardsGrantedInYearMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_exls_AddYearendValueOfUnvestedEquityAwardsGrantedInYearMember" xml:lang="en-US">Add yearend value of unvested equity awards granted in year [Member]</label>
<labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="loc_exls_AddYearendValueOfUnvestedEquityAwardsGrantedInYearMember" xlink:to="lab_exls_AddYearendValueOfUnvestedEquityAwardsGrantedInYearMember" />
<loc xlink:type="locator" xlink:href="exls-20221231.xsd#exls_AddChangeInValueOfUnvestedEquityAwardsGrantedInPriorYearsMember" xlink:label="loc_exls_AddChangeInValueOfUnvestedEquityAwardsGrantedInPriorYearsMember" />
<label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="lab_exls_AddChangeInValueOfUnvestedEquityAwardsGrantedInPriorYearsMember" xml:lang="en-US">Add change in value of unvested equity awards granted in prior years [Member]</label>
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