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

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2024-04-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000101984</issuerCik>
        <issuerName>UNIVERSAL ELECTRONICS INC</issuerName>
        <issuerTradingSymbol>UEIC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001443284</rptOwnerCik>
            <rptOwnerName>Singer Eric</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O IMMERSION CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>2999 N.E. 191ST STREET, SUITE 610</rptOwnerStreet2>
            <rptOwnerCity>AVENTURA</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>33180</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2024-04-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1250</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1403</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1544647</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Group</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2024-04-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1250</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1250</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1250</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Each restricted stock unit represents a contingent right to receive one share of the Issuer's Common Stock.</footnote>
        <footnote id="F2">Shares of the Issuer's Common Stock owned directly by Toro 18. Mr. Singer, as the President and Chief Executive Officer of Toro 18, may be deemed to beneficially own the securities owned directly by Toro 18.</footnote>
        <footnote id="F3">Restricted stock units awarded on January 1, 2024 to Mr. Singer as Director compensation and generally vest and are paid quarterly over a period ending July 1, 2024.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/Eric Singer by Valerie Ballard pursuant to Limited Power of Attorney dated April 1, 2024</signatureName>
        <signatureDate>2024-04-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0508
4
2024-04-01
0
0000101984
UNIVERSAL ELECTRONICS INC
UEIC
0001443284
Singer Eric
C/O IMMERSION CORPORATION
2999 N.E. 191ST STREET, SUITE 610
AVENTURA
FL
33180
1
0
1
0
0
Common Stock
2024-04-01
4
M
0
1250
A
1403
D
Common Stock
1544647
I
By Group
Restricted Stock Units
2024-04-01
4
M
0
1250
0
D
Common Stock
1250
1250
D
Each restricted stock unit represents a contingent right to receive one share of the Issuer's Common Stock.
Shares of the Issuer's Common Stock owned directly by Toro 18. Mr. Singer, as the President and Chief Executive Officer of Toro 18, may be deemed to beneficially own the securities owned directly by Toro 18.
Restricted stock units awarded on January 1, 2024 to Mr. Singer as Director compensation and generally vest and are paid quarterly over a period ending July 1, 2024.
/s/Eric Singer by Valerie Ballard pursuant to Limited Power of Attorney dated April 1, 2024
2024-04-02