<SEC-DOCUMENT>0001900504-25-000003.txt : 20251204
<SEC-HEADER>0001900504-25-000003.hdr.sgml : 20251204
<ACCEPTANCE-DATETIME>20251204162410
ACCESSION NUMBER:		0001900504-25-000003
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20251202
FILED AS OF DATE:		20251204
DATE AS OF CHANGE:		20251204

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Dyer Simon
		CENTRAL INDEX KEY:			0001900504
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-31922
		FILM NUMBER:		251549640

	MAIL ADDRESS:	
		STREET 1:		1000 TEMPUR WAY
		CITY:			LEXINGTON
		STATE:			KY
		ZIP:			40511

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SOMNIGROUP INTERNATIONAL INC.
		CENTRAL INDEX KEY:			0001206264
		STANDARD INDUSTRIAL CLASSIFICATION:	HOUSEHOLD FURNITURE [2510]
		ORGANIZATION NAME:           	04 Manufacturing
		EIN:				331022198
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1000 TEMPUR WAY
		CITY:			LEXINGTON
		STATE:			KY
		ZIP:			40511
		BUSINESS PHONE:		800-878-8889

	MAIL ADDRESS:	
		STREET 1:		1000 TEMPUR WAY
		CITY:			LEXINGTON
		STATE:			KY
		ZIP:			40511

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	TEMPUR SEALY INTERNATIONAL, INC.
		DATE OF NAME CHANGE:	20130614

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	TEMPUR PEDIC INTERNATIONAL INC
		DATE OF NAME CHANGE:	20031202

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	TWI HOLDINGS INC
		DATE OF NAME CHANGE:	20021119
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wk-form4_1764883447.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-12-02</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001206264</issuerCik>
        <issuerName>SOMNIGROUP INTERNATIONAL INC.</issuerName>
        <issuerTradingSymbol>SGI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001900504</rptOwnerCik>
            <rptOwnerName>Dyer Simon</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SOMNIGROUP INTERNATIONAL INC.</rptOwnerStreet1>
            <rptOwnerStreet2>1000 TEMPUR WAY</rptOwnerStreet2>
            <rptOwnerCity>LEXINGTON</rptOwnerCity>
            <rptOwnerState>KY</rptOwnerState>
            <rptOwnerZipCode>40511</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>9245</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2025-12-02</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>29652</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>93.3372</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>34452</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Madad Investments Pty Ltd</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2025-12-02</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2348</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>94.1703</value>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>36800</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Madad Investments Pty Ltd</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $93.00 to $93.99. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the ranges set forth in this footnote.</footnote>
        <footnote id="F2">The reporting person is a shareholder of Madad Investment Pty Ltd and has sole control over the investment and voting decisions of the entity.</footnote>
        <footnote id="F3">The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $94.00 to $94.44. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the ranges set forth in this footnote.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Bhaskar Rao Attorney-in-Fact</signatureName>
        <signatureDate>2025-12-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
