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

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2024-07-30</periodOfReport>

    <issuer>
        <issuerCik>0001851612</issuerCik>
        <issuerName>Focus Impact BH3 Acquisition Co</issuerName>
        <issuerTradingSymbol>BHAC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001851602</rptOwnerCik>
            <rptOwnerName>Crixus BH3 Sponsor, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>819 NE 2ND AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 500</rptOwnerStreet2>
            <rptOwnerCity>FORT LAUDERDALE</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>33304</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>true</isDirector>
            <isTenPercentOwner>true</isTenPercentOwner>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001863939</rptOwnerCik>
            <rptOwnerName>Lebensohn Daniel</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O CRIXUS BH3 SPONSOR, LLC</rptOwnerStreet1>
            <rptOwnerStreet2>819 NE 2ND AVENUE; SUITE 500</rptOwnerStreet2>
            <rptOwnerCity>FORT LAUDERDALE</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>33304</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>true</isDirector>
            <isTenPercentOwner>true</isTenPercentOwner>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001863953</rptOwnerCik>
            <rptOwnerName>Freedman Gregory</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O CRIXUS BH3 SPONSOR, LLC</rptOwnerStreet1>
            <rptOwnerStreet2>819 NE 2ND AVENUE; SUITE 500</rptOwnerStreet2>
            <rptOwnerCity>FORT LAUDERDALE</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>33304</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isTenPercentOwner>true</isTenPercentOwner>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>false</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A common stock</value>
            </securityTitle>
            <transactionDate>
                <value>2024-07-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>450000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1249060</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Class B common stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F3"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2024-07-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>450000</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>450000</value>
                    <footnoteId id="F2"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>111051</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Represents shares of Class A common stock of the Issuer acquired upon conversion of shares of Class B common stock of the Issuer at the Reporting Persons' election.</footnote>
        <footnote id="F2">The securities are held directly by Crixus BH3 Sponsor LLC (&quot;Crixus&quot;). Crixus is controlled by BH3 Management LLC, an entity owned and controlled indirectly by Daniel Lebensohn and Gregory Freedman. Each of Messrs. Lebensohn and Freedman indirectly share voting and dispositive power over the securities held by Crixus and may be deemed to beneficially own the securities held by Crixus. Mr. Lebensohn and Mr. Freedman disclaim beneficial ownership of the securities held by Crixus except to the extent of their pecuniary interest therein.</footnote>
        <footnote id="F3">The shares of Class B Common Stock have no expiration date and will automatically convert into shares of Class A Common Stock at the time of the Issuer's initial business combination, or earlier at the option of the holder, on a one-for-one basis, subject to adjustment as set forth in the Issuer's registration statement on Form S-1 (File No. 333-259269).</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Gregory Freedman, as Authorized Signatory for Crixus BH3 Sponsor, LLC</signatureName>
        <signatureDate>2024-08-01</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Daniel Lebensohn</signatureName>
        <signatureDate>2024-08-01</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Gregory Freedman</signatureName>
        <signatureDate>2024-08-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
