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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019ece0c-828e-7d5a-9874-059d047c4977,g:da4df6fc-f783-4267-a393-fc6a3f4ab216-->
<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" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:roleRef roleURI="http://www.newmountainfinance.com/role/Cover" xlink:type="simple" xlink:href="nmfc-20260803.xsd#Cover"/>
  <link:presentationLink xlink:role="http://www.newmountainfinance.com/role/Cover" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_CoverAbstract_019ece0c-828e-7395-9221-1ea0129e15d3" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CoverAbstract"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityListingsTable_019ece0c-828e-7926-adb7-ed0245e948d7" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityListingsTable"/>
    <link:presentationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_CoverAbstract_019ece0c-828e-7395-9221-1ea0129e15d3" xlink:to="loc_dei_EntityListingsTable_019ece0c-828e-7926-adb7-ed0245e948d7" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019ece0c-828e-71cf-98aa-16937030b96f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:presentationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityListingsTable_019ece0c-828e-7926-adb7-ed0245e948d7" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019ece0c-828e-71cf-98aa-16937030b96f" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019ece0c-828e-750d-9463-a802bd89a88c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ClassOfStockDomain"/>
    <link:presentationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019ece0c-828e-71cf-98aa-16937030b96f" xlink:to="loc_us-gaap_ClassOfStockDomain_019ece0c-828e-750d-9463-a802bd89a88c" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019ece0c-828e-75b2-8baf-46a4ac337bf5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember"/>
    <link:presentationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ClassOfStockDomain_019ece0c-828e-750d-9463-a802bd89a88c" xlink:to="loc_us-gaap_CommonStockMember_019ece0c-828e-75b2-8baf-46a4ac337bf5" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_nmfc_EightPointTwoFivePercentageNotesDueTwoThousandTwentyEightMember_019ece0c-828e-70f3-bf25-563c9a8a62fc" xlink:href="nmfc-20260803.xsd#nmfc_EightPointTwoFivePercentageNotesDueTwoThousandTwentyEightMember"/>
    <link:presentationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_us-gaap_ClassOfStockDomain_019ece0c-828e-750d-9463-a802bd89a88c" xlink:to="loc_nmfc_EightPointTwoFivePercentageNotesDueTwoThousandTwentyEightMember_019ece0c-828e-70f3-bf25-563c9a8a62fc" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityListingsLineItems_019ece0c-828e-7ee7-ba64-03cb868301e4" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityListingsLineItems"/>
    <link:presentationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityListingsTable_019ece0c-828e-7926-adb7-ed0245e948d7" xlink:to="loc_dei_EntityListingsLineItems_019ece0c-828e-7ee7-ba64-03cb868301e4" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_019ece0c-828e-7246-bbe9-bf5bad47b150" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentType"/>
    <link:presentationArc order="1" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityListingsLineItems_019ece0c-828e-7ee7-ba64-03cb868301e4" xlink:to="loc_dei_DocumentType_019ece0c-828e-7246-bbe9-bf5bad47b150" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_019ece0c-828e-7d70-86bb-bfff42f2edcc" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_DocumentPeriodEndDate"/>
    <link:presentationArc order="2" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityListingsLineItems_019ece0c-828e-7ee7-ba64-03cb868301e4" xlink:to="loc_dei_DocumentPeriodEndDate_019ece0c-828e-7d70-86bb-bfff42f2edcc" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_019ece0c-828e-7dac-a588-29de82619ea4" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityRegistrantName"/>
    <link:presentationArc order="3" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityListingsLineItems_019ece0c-828e-7ee7-ba64-03cb868301e4" xlink:to="loc_dei_EntityRegistrantName_019ece0c-828e-7dac-a588-29de82619ea4" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_019ece0c-828e-700d-8737-dde07ecc07b8" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:presentationArc order="4" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityListingsLineItems_019ece0c-828e-7ee7-ba64-03cb868301e4" xlink:to="loc_dei_EntityIncorporationStateCountryCode_019ece0c-828e-700d-8737-dde07ecc07b8" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_019ece0c-828e-7081-bed8-43ce7a870e68" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityFileNumber"/>
    <link:presentationArc order="5" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityListingsLineItems_019ece0c-828e-7ee7-ba64-03cb868301e4" xlink:to="loc_dei_EntityFileNumber_019ece0c-828e-7081-bed8-43ce7a870e68" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_019ece0c-828e-7acb-b192-c396ac24f6fb" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:presentationArc order="6" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityListingsLineItems_019ece0c-828e-7ee7-ba64-03cb868301e4" xlink:to="loc_dei_EntityTaxIdentificationNumber_019ece0c-828e-7acb-b192-c396ac24f6fb" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_019ece0c-828e-754b-858b-cde6c8979047" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressAddressLine1"/>
    <link:presentationArc order="7" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityListingsLineItems_019ece0c-828e-7ee7-ba64-03cb868301e4" xlink:to="loc_dei_EntityAddressAddressLine1_019ece0c-828e-754b-858b-cde6c8979047" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_019ece0c-828e-734b-a770-0832a8576cf0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressCityOrTown"/>
    <link:presentationArc order="8" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityListingsLineItems_019ece0c-828e-7ee7-ba64-03cb868301e4" xlink:to="loc_dei_EntityAddressCityOrTown_019ece0c-828e-734b-a770-0832a8576cf0" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_019ece0c-828e-7ee2-b567-fe1343f728cd" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressStateOrProvince"/>
    <link:presentationArc order="9" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityListingsLineItems_019ece0c-828e-7ee7-ba64-03cb868301e4" xlink:to="loc_dei_EntityAddressStateOrProvince_019ece0c-828e-7ee2-b567-fe1343f728cd" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_019ece0c-828e-7f4b-abac-499c5e5849b0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityAddressPostalZipCode"/>
    <link:presentationArc order="10" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityListingsLineItems_019ece0c-828e-7ee7-ba64-03cb868301e4" xlink:to="loc_dei_EntityAddressPostalZipCode_019ece0c-828e-7f4b-abac-499c5e5849b0" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_019ece0c-828e-7428-b1b8-4b286b53a4b0" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_CityAreaCode"/>
    <link:presentationArc order="11" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityListingsLineItems_019ece0c-828e-7ee7-ba64-03cb868301e4" xlink:to="loc_dei_CityAreaCode_019ece0c-828e-7428-b1b8-4b286b53a4b0" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_019ece0c-828e-7eed-9d30-3979711a8d1f" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LocalPhoneNumber"/>
    <link:presentationArc order="12" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityListingsLineItems_019ece0c-828e-7ee7-ba64-03cb868301e4" xlink:to="loc_dei_LocalPhoneNumber_019ece0c-828e-7eed-9d30-3979711a8d1f" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_WrittenCommunications_019ece0c-828e-73a9-8dc7-4495f7dac918" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_WrittenCommunications"/>
    <link:presentationArc order="13" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityListingsLineItems_019ece0c-828e-7ee7-ba64-03cb868301e4" xlink:to="loc_dei_WrittenCommunications_019ece0c-828e-73a9-8dc7-4495f7dac918" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SolicitingMaterial_019ece0c-828e-746f-8cca-8197a51fcf2c" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_SolicitingMaterial"/>
    <link:presentationArc order="14" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityListingsLineItems_019ece0c-828e-7ee7-ba64-03cb868301e4" xlink:to="loc_dei_SolicitingMaterial_019ece0c-828e-746f-8cca-8197a51fcf2c" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_PreCommencementTenderOffer_019ece0c-828e-79b1-8370-62dee60ad473" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_PreCommencementTenderOffer"/>
    <link:presentationArc order="15" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityListingsLineItems_019ece0c-828e-7ee7-ba64-03cb868301e4" xlink:to="loc_dei_PreCommencementTenderOffer_019ece0c-828e-79b1-8370-62dee60ad473" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_PreCommencementIssuerTenderOffer_019ece0c-828e-7410-9dad-799e966ca22e" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_PreCommencementIssuerTenderOffer"/>
    <link:presentationArc order="16" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityListingsLineItems_019ece0c-828e-7ee7-ba64-03cb868301e4" xlink:to="loc_dei_PreCommencementIssuerTenderOffer_019ece0c-828e-7410-9dad-799e966ca22e" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_019ece0c-828e-77d6-83ff-e485cb9576e3" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_Security12bTitle"/>
    <link:presentationArc order="17" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityListingsLineItems_019ece0c-828e-7ee7-ba64-03cb868301e4" xlink:to="loc_dei_Security12bTitle_019ece0c-828e-77d6-83ff-e485cb9576e3" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_019ece0c-828e-7ac6-bed7-cd049f4d4c29" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_TradingSymbol"/>
    <link:presentationArc order="18" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityListingsLineItems_019ece0c-828e-7ee7-ba64-03cb868301e4" xlink:to="loc_dei_TradingSymbol_019ece0c-828e-7ac6-bed7-cd049f4d4c29" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_019ece0c-828e-7fe9-a139-d8474dbc2b68" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_SecurityExchangeName"/>
    <link:presentationArc order="19" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityListingsLineItems_019ece0c-828e-7ee7-ba64-03cb868301e4" xlink:to="loc_dei_SecurityExchangeName_019ece0c-828e-7fe9-a139-d8474dbc2b68" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_019ece0c-828e-764c-aa90-f3c579e0ee62" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:presentationArc order="20" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityListingsLineItems_019ece0c-828e-7ee7-ba64-03cb868301e4" xlink:to="loc_dei_EntityEmergingGrowthCompany_019ece0c-828e-764c-aa90-f3c579e0ee62" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_019ece0c-828e-776f-89e0-34b510202143" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityCentralIndexKey"/>
    <link:presentationArc order="21" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityListingsLineItems_019ece0c-828e-7ee7-ba64-03cb868301e4" xlink:to="loc_dei_EntityCentralIndexKey_019ece0c-828e-776f-89e0-34b510202143" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_019ece0c-828e-725a-8c3c-3dea97ce05e5" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_AmendmentFlag"/>
    <link:presentationArc order="22" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="loc_dei_EntityListingsLineItems_019ece0c-828e-7ee7-ba64-03cb868301e4" xlink:to="loc_dei_AmendmentFlag_019ece0c-828e-725a-8c3c-3dea97ce05e5" xlink:type="arc" preferredLabel="http://www.xbrl.org/2003/role/terseLabel"/>
  </link:presentationLink>
</link:linkbase>
