<?xml version="1.0"?>
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    <schemaVersion>X0708</schemaVersion>

    <submissionType>D/A</submissionType>

    <testOrLive>LIVE</testOrLive>

    <primaryIssuer>
        <cik>0002013810</cik>
        <entityName>BlackRock USD Institutional Digital Liquidity Fund Ltd.</entityName>
        <issuerAddress>
            <street1>50 HUDSON YARDS</street1>
            <city>NEW YORK</city>
            <stateOrCountry>NY</stateOrCountry>
            <stateOrCountryDescription>NEW YORK</stateOrCountryDescription>
            <zipCode>10001</zipCode>
        </issuerAddress>
        <issuerPhoneNumber>(212) 810-5300</issuerPhoneNumber>
        <jurisdictionOfInc>VIRGIN ISLANDS, BRITISH</jurisdictionOfInc>
        <issuerPreviousNameList>
            <value>None</value>
        </issuerPreviousNameList>
        <edgarPreviousNameList>
            <value>None</value>
        </edgarPreviousNameList>
        <entityType>Other</entityType>
        <entityTypeOtherDesc>Limited Company</entityTypeOtherDesc>
        <yearOfInc>
            <withinFiveYears>true</withinFiveYears>
            <value>2023</value>
        </yearOfInc>
    </primaryIssuer>

    <relatedPersonsList>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Ian</firstName>
                <lastName>Pilgrim</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>Williams House, 4th Floor</street1>
                <street2>20 Reid Street</street2>
                <city>Hamilton</city>
                <stateOrCountry>D0</stateOrCountry>
                <stateOrCountryDescription>BERMUDA</stateOrCountryDescription>
                <zipCode>HM11</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Director</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification></relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>W.</firstName>
                <middleName>William</middleName>
                <lastName>Woods</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>c/o Paradigm Governance Partners Ltd.</street1>
                <street2>3rd Fl., One Capital Pl., 136 Shedden Rd</street2>
                <city>George Town</city>
                <stateOrCountry>E9</stateOrCountry>
                <stateOrCountryDescription>CAYMAN ISLANDS</stateOrCountryDescription>
                <zipCode>KY1-9006</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Director</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification></relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Noelle</firstName>
                <lastName>L'Heureux</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>400 Howard Street</street1>
                <city>San Franciso</city>
                <stateOrCountry>CA</stateOrCountry>
                <stateOrCountryDescription>CALIFORNIA</stateOrCountryDescription>
                <zipCode>94105</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Director</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification></relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Jennifer</firstName>
                <lastName>Collins</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>Carne Group,Winward 3, Regatta Office Pk</street1>
                <street2>West Bay Road, PO Box 30872</street2>
                <city>Grand Cayman</city>
                <stateOrCountry>E9</stateOrCountry>
                <stateOrCountryDescription>CAYMAN ISLANDS</stateOrCountryDescription>
                <zipCode>KY1-1204</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Director</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification></relationshipClarification>
        </relatedPersonInfo>
    </relatedPersonsList>

    <offeringData>
        <industryGroup>
            <industryGroupType>Pooled Investment Fund</industryGroupType>
            <investmentFundInfo>
                <investmentFundType>Other Investment Fund</investmentFundType>
                <is40Act>false</is40Act>
            </investmentFundInfo>
        </industryGroup>
        <issuerSize>
            <aggregateNetAssetValueRange>Decline to Disclose</aggregateNetAssetValueRange>
        </issuerSize>
        <federalExemptionsExclusions>
            <item>06c</item>
            <item>3C</item>
            <item>3C.7</item>
        </federalExemptionsExclusions>
        <typeOfFiling>
            <newOrAmendment>
                <isAmendment>true</isAmendment>
                <previousAccessionNumber>0002004687-25-000001</previousAccessionNumber>
            </newOrAmendment>
            <dateOfFirstSale>
                <value>2024-03-04</value>
            </dateOfFirstSale>
        </typeOfFiling>
        <durationOfOffering>
            <moreThanOneYear>true</moreThanOneYear>
        </durationOfOffering>
        <typesOfSecuritiesOffered>
            <isPooledInvestmentFundType>true</isPooledInvestmentFundType>
        </typesOfSecuritiesOffered>
        <businessCombinationTransaction>
            <isBusinessCombinationTransaction>false</isBusinessCombinationTransaction>
            <clarificationOfResponse></clarificationOfResponse>
        </businessCombinationTransaction>
        <minimumInvestmentAccepted>100000</minimumInvestmentAccepted>
        <salesCompensationList>
            <recipient>
                <recipientName>Securitize Markets, LLC</recipientName>
                <recipientCRDNumber>283256</recipientCRDNumber>
                <associatedBDName>None</associatedBDName>
                <associatedBDCRDNumber>None</associatedBDCRDNumber>
                <recipientAddress>
                    <street1>701 S Miami Ave</street1>
                    <street2>Brickell City Cent C/O Wework</street2>
                    <city>Miami</city>
                    <stateOrCountry>FL</stateOrCountry>
                    <stateOrCountryDescription>FLORIDA</stateOrCountryDescription>
                    <zipCode>33131</zipCode>
                </recipientAddress>
                <statesOfSolicitationList>
                    <value>All States</value>
                </statesOfSolicitationList>
                <foreignSolicitation>false</foreignSolicitation>
            </recipient>
        </salesCompensationList>
        <offeringSalesAmounts>
            <totalOfferingAmount>Indefinite</totalOfferingAmount>
            <totalAmountSold>5135523412</totalAmountSold>
            <totalRemaining>Indefinite</totalRemaining>
            <clarificationOfResponse></clarificationOfResponse>
        </offeringSalesAmounts>
        <investors>
            <hasNonAccreditedInvestors>false</hasNonAccreditedInvestors>
            <totalNumberAlreadyInvested>28</totalNumberAlreadyInvested>
        </investors>
        <salesCommissionsFindersFees>
            <salesCommissions>
                <dollarAmount>525000</dollarAmount>
                <isEstimate>true</isEstimate>
            </salesCommissions>
            <findersFees>
                <dollarAmount>0</dollarAmount>
            </findersFees>
            <clarificationOfResponse></clarificationOfResponse>
        </salesCommissionsFindersFees>
        <useOfProceeds>
            <grossProceedsUsed>
                <dollarAmount>0</dollarAmount>
            </grossProceedsUsed>
            <clarificationOfResponse></clarificationOfResponse>
        </useOfProceeds>
        <signatureBlock>
            <authorizedRepresentative>false</authorizedRepresentative>
            <signature>
                <issuerName>BlackRock USD Institutional Digital Liquidity Fund Ltd.</issuerName>
                <signatureName>/s/ Noelle L'Heureux</signatureName>
                <nameOfSigner>Noelle L'Heureux</nameOfSigner>
                <signatureTitle>Director</signatureTitle>
                <signatureDate>2026-07-23</signatureDate>
            </signature>
        </signatureBlock>
    </offeringData>
</edgarSubmission>
