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

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-01-31</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000736772</issuerCik>
        <issuerName>CNB FINANCIAL CORP/PA</issuerName>
        <issuerTradingSymbol>CCNE</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001782113</rptOwnerCik>
            <rptOwnerName>Griffith Martin T.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>31 S 2ND STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CLEARFIELD</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>16830</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>SEVP/Chief Revenue Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2025-01-31</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value>E</value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>809</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>25.30</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>9779</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4068.932</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By 401K Plan</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Depositary Shares</value>
                <footnoteId id="F3"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3637</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Reflects shares of common stock surrendered to the Issuer to satisfy tax withholding obligations in connection with the Restricted Stock Award.</footnote>
        <footnote id="F2">The amount of securities beneficially owned have been adjusted to reflect the latest plan statement.</footnote>
        <footnote id="F3">Each Depositary Share represents a 1/40th interest in a share of the Issuer's 7.125% Series A Fixed-Rate Non-Cumulative Perpetual Preferred Stock, no par value per share.  Depositary Shares were purchased in an underwritten public offering.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Jessica A. Zupich, Attorney-in-Fact</signatureName>
        <signatureDate>2025-02-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0508
4
2025-01-31
0
0000736772
CNB FINANCIAL CORP/PA
CCNE
0001782113
Griffith Martin T.
31 S 2ND STREET
CLEARFIELD
PA
16830
0
1
0
0
SEVP/Chief Revenue Officer
0
Common Stock
2025-01-31
5
F
0
E
809
25.30
D
9779
D
Common Stock
4068.932
I
By 401K Plan
Depositary Shares
3637
D
Reflects shares of common stock surrendered to the Issuer to satisfy tax withholding obligations in connection with the Restricted Stock Award.
The amount of securities beneficially owned have been adjusted to reflect the latest plan statement.
Each Depositary Share represents a 1/40th interest in a share of the Issuer's 7.125% Series A Fixed-Rate Non-Cumulative Perpetual Preferred Stock, no par value per share.  Depositary Shares were purchased in an underwritten public offering.
/s/ Jessica A. Zupich, Attorney-in-Fact
2025-02-03