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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2025 Workiva-->
<!--r:3b2fc866-44e2-4c22-9f14-1b5f4275575e,g:06e589e1-f09b-4d35-b316-b2db6755a780-->
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:newt="http://www.newtekone.com/20250424" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:dtr-types="http://www.xbrl.org/dtr/type/2022-03-31" attributeFormDefault="unqualified" elementFormDefault="qualified" targetNamespace="http://www.newtekone.com/20250424">
  <xs:import namespace="http://www.xbrl.org/2003/instance" schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd"/>
  <xs:import namespace="http://www.xbrl.org/2003/linkbase" schemaLocation="http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd"/>
  <xs:import namespace="http://www.xbrl.org/dtr/type/2022-03-31" schemaLocation="https://www.xbrl.org/dtr/type/2022-03-31/types.xsd"/>
  <xs:import namespace="http://xbrl.sec.gov/dei-sub/2024" schemaLocation="https://xbrl.sec.gov/dei/2024/dei-sub-2024.xsd"/>
  <xs:import namespace="http://xbrl.sec.gov/ecd-sub/2024" schemaLocation="https://xbrl.sec.gov/ecd/2024/ecd-sub-2024.xsd"/>
  <xs:annotation>
    <xs:appinfo>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="newt-20250424_pre.xml" xlink:role="http://www.xbrl.org/2003/role/presentationLinkbaseRef" xlink:type="simple"/>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="newt-20250424_lab.xml" xlink:role="http://www.xbrl.org/2003/role/labelLinkbaseRef" xlink:type="simple"/>
    </xs:appinfo>
  </xs:annotation>
  <xs:element id="newt_TotalShareholderReturnPercentage" abstract="false" name="TotalShareholderReturnPercentage" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="newt_TotalShareholderReturnPercentagePeerGroup" abstract="false" name="TotalShareholderReturnPercentagePeerGroup" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
</xs:schema>
