<?xml version="1.0"?>
<edgarSubmission>

    <schemaVersion>X0708</schemaVersion>

    <submissionType>D</submissionType>

    <testOrLive>LIVE</testOrLive>

    <primaryIssuer>
        <cik>0002147309</cik>
        <entityName>Princeton Equity Partners III-A, LP</entityName>
        <issuerAddress>
            <street1>C/O PRINCETON EQUITY ADVISORS, LP</street1>
            <street2>47 HULFISH STREET, SUITE 300</street2>
            <city>PRINCETON</city>
            <stateOrCountry>NJ</stateOrCountry>
            <stateOrCountryDescription>NEW JERSEY</stateOrCountryDescription>
            <zipCode>08542</zipCode>
        </issuerAddress>
        <issuerPhoneNumber>609-454-5700</issuerPhoneNumber>
        <jurisdictionOfInc>DELAWARE</jurisdictionOfInc>
        <issuerPreviousNameList>
            <value>None</value>
        </issuerPreviousNameList>
        <edgarPreviousNameList>
            <value>None</value>
        </edgarPreviousNameList>
        <entityType>Limited Partnership</entityType>
        <yearOfInc>
            <withinFiveYears>true</withinFiveYears>
            <value>2026</value>
        </yearOfInc>
    </primaryIssuer>

    <relatedPersonsList>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>JAMES</firstName>
                <lastName>WASKOVICH</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>47 HULFISH STREET, SUITE 300</street1>
                <city>PRINCETON</city>
                <stateOrCountry>NJ</stateOrCountry>
                <stateOrCountryDescription>NEW JERSEY</stateOrCountryDescription>
                <zipCode>08542</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>Managing Member of the UGP</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>DOUGLAS</firstName>
                <lastName>KENNEALEY</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>2601 OLIVE STREET, SUITE 1400</street1>
                <city>DALLAS</city>
                <stateOrCountry>TX</stateOrCountry>
                <stateOrCountryDescription>TEXAS</stateOrCountryDescription>
                <zipCode>75201</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>Managing Member of the UGP</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>N/A</firstName>
                <lastName>Princeton Equity Partners GP III, LP</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>47 HULFISH STREET, SUITE 300</street1>
                <city>PRINCETON</city>
                <stateOrCountry>NJ</stateOrCountry>
                <stateOrCountryDescription>NEW JERSEY</stateOrCountryDescription>
                <zipCode>08542</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>The general partner of the Issuer (the &quot;General Partner&quot;)</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>N/A</firstName>
                <lastName>Princeton Equity Group, LLC</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>47 HULFISH STREET, SUITE 300</street1>
                <city>PRINCETON</city>
                <stateOrCountry>NJ</stateOrCountry>
                <stateOrCountryDescription>NEW JERSEY</stateOrCountryDescription>
                <zipCode>08542</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>The general partner of the General Partner (&quot;the UGP&quot;)</relationshipClarification>
        </relatedPersonInfo>
    </relatedPersonsList>

    <offeringData>
        <industryGroup>
            <industryGroupType>Pooled Investment Fund</industryGroupType>
            <investmentFundInfo>
                <investmentFundType>Private Equity Fund</investmentFundType>
                <is40Act>false</is40Act>
            </investmentFundInfo>
        </industryGroup>
        <issuerSize>
            <revenueRange>Decline to Disclose</revenueRange>
        </issuerSize>
        <federalExemptionsExclusions>
            <item>06b</item>
            <item>3C</item>
            <item>3C.7</item>
        </federalExemptionsExclusions>
        <typeOfFiling>
            <newOrAmendment>
                <isAmendment>false</isAmendment>
            </newOrAmendment>
            <dateOfFirstSale>
                <value>2026-09-25</value>
            </dateOfFirstSale>
        </typeOfFiling>
        <durationOfOffering>
            <moreThanOneYear>false</moreThanOneYear>
        </durationOfOffering>
        <typesOfSecuritiesOffered>
            <isPooledInvestmentFundType>true</isPooledInvestmentFundType>
        </typesOfSecuritiesOffered>
        <businessCombinationTransaction>
            <isBusinessCombinationTransaction>false</isBusinessCombinationTransaction>
            <clarificationOfResponse></clarificationOfResponse>
        </businessCombinationTransaction>
        <minimumInvestmentAccepted>250000</minimumInvestmentAccepted>
        <salesCompensationList>
            <recipient>
                <recipientName>LAZARD FRERES &amp; CO. LLC</recipientName>
                <recipientCRDNumber>2528</recipientCRDNumber>
                <associatedBDName>None</associatedBDName>
                <associatedBDCRDNumber>None</associatedBDCRDNumber>
                <recipientAddress>
                    <street1>30 ROCKEFELLER PLAZA</street1>
                    <city>NEW YORK</city>
                    <stateOrCountry>NY</stateOrCountry>
                    <stateOrCountryDescription>NEW YORK</stateOrCountryDescription>
                    <zipCode>10020</zipCode>
                </recipientAddress>
                <statesOfSolicitationList>
                    <value>All States</value>
                </statesOfSolicitationList>
                <foreignSolicitation>false</foreignSolicitation>
            </recipient>
        </salesCompensationList>
        <offeringSalesAmounts>
            <totalOfferingAmount>1256650000</totalOfferingAmount>
            <totalAmountSold>1256650000</totalAmountSold>
            <totalRemaining>0</totalRemaining>
            <clarificationOfResponse>The Total Amount Sold includes interests sold by the Issuer and its parallel fund, Princeton Equity Partners III, LP.</clarificationOfResponse>
        </offeringSalesAmounts>
        <investors>
            <hasNonAccreditedInvestors>false</hasNonAccreditedInvestors>
            <totalNumberAlreadyInvested>48</totalNumberAlreadyInvested>
        </investors>
        <salesCommissionsFindersFees>
            <salesCommissions>
                <dollarAmount>4883287</dollarAmount>
            </salesCommissions>
            <findersFees>
                <dollarAmount>0</dollarAmount>
                <isEstimate>true</isEstimate>
            </findersFees>
            <clarificationOfResponse>The recipient listed in item 12 above will receive the above fee, payable in installments, with respect to certain investors in the issuer and investors in its parallel fund, Princeton Equity Partners III, LP.</clarificationOfResponse>
        </salesCommissionsFindersFees>
        <useOfProceeds>
            <grossProceedsUsed>
                <dollarAmount>0</dollarAmount>
                <isEstimate>true</isEstimate>
            </grossProceedsUsed>
            <clarificationOfResponse>An affiliate of the General Partner will receive a management fee payable by the Issuer quarterly in advance as specified in the Issuer's partnership agreement.</clarificationOfResponse>
        </useOfProceeds>
        <signatureBlock>
            <authorizedRepresentative>false</authorizedRepresentative>
            <signature>
                <issuerName>Princeton Equity Partners III-A, LP</issuerName>
                <signatureName>/s/ JAMES WASKOVICH</signatureName>
                <nameOfSigner>JAMES WASKOVICH</nameOfSigner>
                <signatureTitle>Managing Member of the UGP</signatureTitle>
                <signatureDate>2026-10-08</signatureDate>
            </signature>
        </signatureBlock>
    </offeringData>
</edgarSubmission>
