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

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-05-14</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001798842</rptOwnerCik>
            <rptOwnerName>Dixon Gregory M</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>EVP/Chief Credit Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2025-05-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value>E</value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1976</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>22.83</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>17460.438</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Depositary Shares</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7295.519</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By 401k Plan</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">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>
        <footnote id="F2">The amount of securities beneficially owned have been adjusted to reflect the latest 401K plan statement.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Jessica A. Zupich, Attorney-in-Fact</signatureName>
        <signatureDate>2025-05-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0508
4
2025-05-14
0
0000736772
CNB FINANCIAL CORP/PA
CCNE
0001798842
Dixon Gregory M
31 S 2ND STREET
CLEARFIELD
PA
16830
0
1
0
0
EVP/Chief Credit Officer
0
Common Stock
2025-05-14
5
A
0
E
1976
22.83
A
17460.438
D
Depositary Shares
1000
D
Common Stock
7295.519
I
By 401k Plan
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.
The amount of securities beneficially owned have been adjusted to reflect the latest 401K plan statement.
/s/ Jessica A. Zupich, Attorney-in-Fact
2025-05-15