<?xml version="1.0" encoding="UTF-8"?>
<edgarSubmission xmlns:com="http://www.sec.gov/edgar/common" xmlns="http://www.sec.gov/edgar/thirteenffiler">
  <schemaVersion>X0202</schemaVersion>
  <headerData>
    <submissionType>13F-HR</submissionType>
    <filerInfo>
      <liveTestFlag>LIVE</liveTestFlag>
      <filer>
        <credentials>
          <cik>0001269978</cik>
          <ccc>XXXXXXXX</ccc>
        </credentials>
      </filer>
      <periodOfReport>12-31-2023</periodOfReport>
    </filerInfo>
  </headerData>
  <formData>
    <coverPage>
      <reportCalendarOrQuarter>12-31-2023</reportCalendarOrQuarter>
      <isAmendment>false</isAmendment>
      <filingManager>
        <name>Alesco Advisors LLC</name>
        <address>
          <com:street1>120 Office Park Way</com:street1>
          <com:city>Pittsford</com:city>
          <com:stateOrCountry>NY</com:stateOrCountry>
          <com:zipCode>14534</com:zipCode>
        </address>
      </filingManager>
      <reportType>13F HOLDINGS REPORT</reportType>
      <form13FFileNumber>028-10620</form13FFileNumber>
      <provideInfoForInstruction5>N</provideInfoForInstruction5>
    </coverPage>
    <signatureBlock>
      <name>Benton F. Kircher</name>
      <title>Chief Compliance Officer</title>
      <phone>(585) 586-0970</phone>
      <signature>/s/ Benton F. Kircher</signature>
      <city>Pittsford</city>
      <stateOrCountry>NY</stateOrCountry>
      <signatureDate>02-02-2024</signatureDate>
    </signatureBlock>
    <summaryPage>
      <otherIncludedManagersCount>0</otherIncludedManagersCount>
      <tableEntryTotal>176</tableEntryTotal>
      <tableValueTotal>2851562645</tableValueTotal>
    </summaryPage>
  </formData>
</edgarSubmission>
