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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2024 Workiva-->
<!--r:5b1105f9-a266-498c-8eff-9585009e90b8,g:f4e5c7ee-43f9-485b-83bd-bfd6fc577768-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://emergentbiosolutions.com/role/CoverPageCoverPage" xlink:type="simple" xlink:href="ebs-20240229.xsd#CoverPageCoverPage"/>
  <link:definitionLink xlink:role="http://emergentbiosolutions.com/role/CoverPageCoverPage" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressesLineItems_0bfe4f18-0340-4504-9246-f8da8097376a" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressesTable_2853c2f9-083e-479e-8132-5f77f8e007b3" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_EntityAddressesLineItems_0bfe4f18-0340-4504-9246-f8da8097376a" xlink:to="loc_dei_EntityAddressesTable_2853c2f9-083e-479e-8132-5f77f8e007b3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressesAddressTypeAxis_e7399c6b-9773-46e4-816d-d3e68cec8c76" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressesAddressTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_EntityAddressesTable_2853c2f9-083e-479e-8132-5f77f8e007b3" xlink:to="loc_dei_EntityAddressesAddressTypeAxis_e7399c6b-9773-46e4-816d-d3e68cec8c76" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AddressTypeDomain_e7399c6b-9773-46e4-816d-d3e68cec8c76_default" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_AddressTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_EntityAddressesAddressTypeAxis_e7399c6b-9773-46e4-816d-d3e68cec8c76" xlink:to="loc_dei_AddressTypeDomain_e7399c6b-9773-46e4-816d-d3e68cec8c76_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AddressTypeDomain_d7163ad6-84df-4a54-aaf6-628b080e88fd" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_AddressTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_EntityAddressesAddressTypeAxis_e7399c6b-9773-46e4-816d-d3e68cec8c76" xlink:to="loc_dei_AddressTypeDomain_d7163ad6-84df-4a54-aaf6-628b080e88fd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_FormerAddressMember_418e0610-a68b-4b7a-882c-1068090345b2" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_FormerAddressMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_AddressTypeDomain_d7163ad6-84df-4a54-aaf6-628b080e88fd" xlink:to="loc_dei_FormerAddressMember_418e0610-a68b-4b7a-882c-1068090345b2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_c8b53227-1ad8-4693-a03b-f17e34116b84" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentType"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityAddressesLineItems_0bfe4f18-0340-4504-9246-f8da8097376a" xlink:to="loc_dei_DocumentType_c8b53227-1ad8-4693-a03b-f17e34116b84" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_78370ad4-77da-4268-85dd-ebfb9589c2c9" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_DocumentPeriodEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityAddressesLineItems_0bfe4f18-0340-4504-9246-f8da8097376a" xlink:to="loc_dei_DocumentPeriodEndDate_78370ad4-77da-4268-85dd-ebfb9589c2c9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_f151b564-fee6-4d3b-9344-1c6537695047" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityRegistrantName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityAddressesLineItems_0bfe4f18-0340-4504-9246-f8da8097376a" xlink:to="loc_dei_EntityRegistrantName_f151b564-fee6-4d3b-9344-1c6537695047" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_e08a6919-f9d2-47a0-8407-4a182d9f2b5d" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityAddressesLineItems_0bfe4f18-0340-4504-9246-f8da8097376a" xlink:to="loc_dei_EntityIncorporationStateCountryCode_e08a6919-f9d2-47a0-8407-4a182d9f2b5d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_068f6e43-9e19-4734-9281-ec0b0be46223" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityFileNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityAddressesLineItems_0bfe4f18-0340-4504-9246-f8da8097376a" xlink:to="loc_dei_EntityFileNumber_068f6e43-9e19-4734-9281-ec0b0be46223" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_0823d9f4-27d2-4eff-a566-bda0ed7b4835" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityAddressesLineItems_0bfe4f18-0340-4504-9246-f8da8097376a" xlink:to="loc_dei_EntityTaxIdentificationNumber_0823d9f4-27d2-4eff-a566-bda0ed7b4835" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_967a9c09-307a-41f5-b709-550ad5f93e86" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressAddressLine1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityAddressesLineItems_0bfe4f18-0340-4504-9246-f8da8097376a" xlink:to="loc_dei_EntityAddressAddressLine1_967a9c09-307a-41f5-b709-550ad5f93e86" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine2_e1c064a8-2c2e-4caf-96fb-378fcc1f2c6e" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressAddressLine2"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityAddressesLineItems_0bfe4f18-0340-4504-9246-f8da8097376a" xlink:to="loc_dei_EntityAddressAddressLine2_e1c064a8-2c2e-4caf-96fb-378fcc1f2c6e" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_0a7a5adf-acca-4bee-b1d8-236789d99ea8" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressCityOrTown"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityAddressesLineItems_0bfe4f18-0340-4504-9246-f8da8097376a" xlink:to="loc_dei_EntityAddressCityOrTown_0a7a5adf-acca-4bee-b1d8-236789d99ea8" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_6ac765d6-01e8-4c16-af49-b8931260632e" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressStateOrProvince"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityAddressesLineItems_0bfe4f18-0340-4504-9246-f8da8097376a" xlink:to="loc_dei_EntityAddressStateOrProvince_6ac765d6-01e8-4c16-af49-b8931260632e" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_29e5edb5-1006-4d65-ab19-c3e79f29415b" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityAddressPostalZipCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityAddressesLineItems_0bfe4f18-0340-4504-9246-f8da8097376a" xlink:to="loc_dei_EntityAddressPostalZipCode_29e5edb5-1006-4d65-ab19-c3e79f29415b" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_8884e6c6-d388-4690-aed7-6f85c1470cdd" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_CityAreaCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityAddressesLineItems_0bfe4f18-0340-4504-9246-f8da8097376a" xlink:to="loc_dei_CityAreaCode_8884e6c6-d388-4690-aed7-6f85c1470cdd" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_17582f1d-dd9c-4ec4-a809-7f5e1a1e3c67" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_LocalPhoneNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityAddressesLineItems_0bfe4f18-0340-4504-9246-f8da8097376a" xlink:to="loc_dei_LocalPhoneNumber_17582f1d-dd9c-4ec4-a809-7f5e1a1e3c67" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_WrittenCommunications_39e415e2-b45d-4f15-a0c8-734f0779d61f" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_WrittenCommunications"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityAddressesLineItems_0bfe4f18-0340-4504-9246-f8da8097376a" xlink:to="loc_dei_WrittenCommunications_39e415e2-b45d-4f15-a0c8-734f0779d61f" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SolicitingMaterial_c2438c20-7e31-4a2c-bbbf-55e3947791c1" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_SolicitingMaterial"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityAddressesLineItems_0bfe4f18-0340-4504-9246-f8da8097376a" xlink:to="loc_dei_SolicitingMaterial_c2438c20-7e31-4a2c-bbbf-55e3947791c1" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_PreCommencementTenderOffer_81f93602-9a09-493b-9c98-667679046799" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_PreCommencementTenderOffer"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityAddressesLineItems_0bfe4f18-0340-4504-9246-f8da8097376a" xlink:to="loc_dei_PreCommencementTenderOffer_81f93602-9a09-493b-9c98-667679046799" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_PreCommencementIssuerTenderOffer_ad49ff55-1360-41d0-9497-2207a564ed28" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_PreCommencementIssuerTenderOffer"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityAddressesLineItems_0bfe4f18-0340-4504-9246-f8da8097376a" xlink:to="loc_dei_PreCommencementIssuerTenderOffer_ad49ff55-1360-41d0-9497-2207a564ed28" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_bc4b1f89-67f2-41b7-8fb9-712a848167ba" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityAddressesLineItems_0bfe4f18-0340-4504-9246-f8da8097376a" xlink:to="loc_dei_EntityEmergingGrowthCompany_bc4b1f89-67f2-41b7-8fb9-712a848167ba" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_9f583f19-891f-4e49-9cc8-4522c7c6b36a" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_Security12bTitle"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityAddressesLineItems_0bfe4f18-0340-4504-9246-f8da8097376a" xlink:to="loc_dei_Security12bTitle_9f583f19-891f-4e49-9cc8-4522c7c6b36a" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_89eb0d6f-363e-4361-836a-ff265922af8c" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_TradingSymbol"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityAddressesLineItems_0bfe4f18-0340-4504-9246-f8da8097376a" xlink:to="loc_dei_TradingSymbol_89eb0d6f-363e-4361-836a-ff265922af8c" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_e70c64a5-bec6-4f8a-a40a-22ccd04a8f93" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_SecurityExchangeName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityAddressesLineItems_0bfe4f18-0340-4504-9246-f8da8097376a" xlink:to="loc_dei_SecurityExchangeName_e70c64a5-bec6-4f8a-a40a-22ccd04a8f93" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_054a387d-947e-476a-bca8-7b73e07a196a" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_EntityCentralIndexKey"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityAddressesLineItems_0bfe4f18-0340-4504-9246-f8da8097376a" xlink:to="loc_dei_EntityCentralIndexKey_054a387d-947e-476a-bca8-7b73e07a196a" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_62848abd-7d77-4178-92a8-34ee21c343c0" xlink:href="https://xbrl.sec.gov/dei/2023/dei-2023.xsd#dei_AmendmentFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityAddressesLineItems_0bfe4f18-0340-4504-9246-f8da8097376a" xlink:to="loc_dei_AmendmentFlag_62848abd-7d77-4178-92a8-34ee21c343c0" xlink:type="arc" order="22"/>
  </link:definitionLink>
</link:linkbase>
