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SEC EDGAR · Insider purchase

ADP: SWAN ROBERT HOLMES reported buying shares

1 reported purchase of non-derivative securities. The filing marks a Rule 10b5-1 trading plan. Code P includes open-market and private purchases; it does not establish motive.

Follow ADP
Became public
May 11, 2026, 4:04 PM EDT
Event / period date
May 7, 2026
Collected
Nov 10, 2026, 8:26 PM EST

Why this is connected

This filing identifies AUTOMATIC DATA PROCESSING INC as the issuer of the security. The company's SEC identifier connects it to ADP.

Reported transactions

SWAN ROBERT HOLMES (Director)

3,619 shares · Common Stock

May 7, 2026 · $206.05 per share

Value calculated from the reported shares and prices: $745,694.95.

The filing marks a Rule 10b5-1 trading plan. Code P covers open-market and private purchases. Grants, option exercises, and tax withholding are excluded from purchase results. Read the source footnotes for ownership and pricing details.

Source evidence

Read the source excerpt or record
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0609</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2026-05-07</periodOfReport>

    <issuer>
        <issuerCik>0000008670</issuerCik>
        <issuerName>AUTOMATIC DATA PROCESSING INC</issuerName>
        <issuerTradingSymbol>ADP</issuerTradingSymbol>
        <issuerForeignTradingSymbol></issuerForeignTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001218363</rptOwnerCik>
            <rptOwnerName>SWAN ROBERT HOLMES</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>false</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>ONE ADP BOULEVARD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>ROSELAND</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>07068</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>1</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2026-05-07</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>3619.0000</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>206.0500</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5072.0000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>115.0000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The transactions reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person in January 2026.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>David Kwon (POA on File)</signatureName>
        <signatureDate>2026-05-11</signatureDate>
    </ownerSignature>
</ownershipDocument>

Congressional trading in ADP

These disclosures provide context. Their presence does not establish a link between a trader and the event.

Original documents control. Public records can be amended, and company connections may require interpretation. Nothing here is investment advice.

ADP: SWAN ROBERT HOLMES reported buying shares | InsiderDB