<SEC-DOCUMENT>0001104659-25-048461.txt : 20250514
<SEC-HEADER>0001104659-25-048461.hdr.sgml : 20250514
<ACCEPTANCE-DATETIME>20250514155218
ACCESSION NUMBER:		0001104659-25-048461
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20250512
FILED AS OF DATE:		20250514
DATE AS OF CHANGE:		20250514

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Frost Mark T
		CENTRAL INDEX KEY:			0001310262
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-33957
		FILM NUMBER:		25944998

	MAIL ADDRESS:	
		STREET 1:		21 CORPORATE CIRCLE
		STREET 2:		PO BOX 15098
		CITY:			ALBANY
		STATE:			NY
		ZIP:			12033-5098

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			HARVARD BIOSCIENCE INC
		CENTRAL INDEX KEY:			0001123494
		STANDARD INDUSTRIAL CLASSIFICATION:	LABORATORY ANALYTICAL INSTRUMENTS [3826]
		ORGANIZATION NAME:           	08 Industrial Applications and Services
		EIN:				043306140
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		84 OCTOBER HILL RD
		CITY:			HOLLISTON
		STATE:			MA
		ZIP:			01746
		BUSINESS PHONE:		5088938999

	MAIL ADDRESS:	
		STREET 1:		84 OCTOBER HILL ROAD
		CITY:			HOLLISTON
		STATE:			MA
		ZIP:			01746
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>tm2514961-2_4seq1.xml
<DESCRIPTION>OWNERSHIP DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-05-12</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001123494</issuerCik>
        <issuerName>HARVARD BIOSCIENCE INC</issuerName>
        <issuerTradingSymbol>HBIO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001310262</rptOwnerCik>
            <rptOwnerName>Frost Mark T</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O HARVARD BIOSCIENCE, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>84 OCTOBER HILL ROAD</rptOwnerStreet2>
            <rptOwnerCity>HOLLISTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>01746</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Interim CFO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2025-05-12</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>100000</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>125000</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents 100,000 restricted stock units that will vest on May 12, 2026.</footnote>
        <footnote id="F2">Includes (a) 100,000 restricted stock units that will vest on May 12, 2026, and (b) 25,000 shares of common stock beneficially owned by the Reporting Person.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ John Fry, by power of attorney</signatureName>
        <signatureDate>2025-05-14</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
