<?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>0001694708</rptOwnerCik>
            <rptOwnerName>Shilling Steven R Shaffner</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>31 S 2ND ST</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 Wealth Mngt 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>10701</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Depositary Shares</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>400</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3987.308</value>
                    <footnoteId id="F3"/>
                </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">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="F3">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
0001694708
Shilling Steven R Shaffner
31 S 2ND ST
CLEARFIELD
PA
16830
0
1
0
0
EVP/Chief Wealth Mngt Officer
0
Common Stock
2025-05-14
5
A
0
E
1976
22.83
A
10701
D
Depositary Shares
400
D
Common Stock
3987.308
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.
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