<SEC-DOCUMENT>0001641172-25-012862.txt : 20250529
<SEC-HEADER>0001641172-25-012862.hdr.sgml : 20250529
<ACCEPTANCE-DATETIME>20250529161510
ACCESSION NUMBER:		0001641172-25-012862
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20250508
FILED AS OF DATE:		20250529
DATE AS OF CHANGE:		20250529

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Ritter Andrew J
		CENTRAL INDEX KEY:			0001631671
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-40023
		FILM NUMBER:		251003537

	MAIL ADDRESS:	
		STREET 1:		C/O RITTER PHARMACEUTICALS INC.
		STREET 2:		1801 CENTURY PARK EAST, SUITE 1820
		CITY:			LOS ANGELES
		STATE:			CA
		ZIP:			90096

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			GT Biopharma, Inc.
		CENTRAL INDEX KEY:			0000109657
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		ORGANIZATION NAME:           	03 Life Sciences
		EIN:				941620407
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		505 MONTGOMERY STREET
		STREET 2:		10TH FLOOR
		CITY:			SAN FRANCISCO
		STATE:			CA
		ZIP:			94111
		BUSINESS PHONE:		(800) 304-9888

	MAIL ADDRESS:	
		STREET 1:		505 MONTGOMERY STREET
		STREET 2:		10TH FLOOR
		CITY:			SAN FRANCISCO
		STATE:			CA
		ZIP:			94111

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	OXIS INTERNATIONAL INC
		DATE OF NAME CHANGE:	19940916

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	DDI PHARMACEUTICALS INC
		DATE OF NAME CHANGE:	19920703

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	DIAGNOSTIC DATA INC /DE/
		DATE OF NAME CHANGE:	19850312
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>ownership.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2025-05-08</periodOfReport>

    <noSecuritiesOwned>1</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000109657</issuerCik>
        <issuerName>GT Biopharma, Inc.</issuerName>
        <issuerTradingSymbol>GTBP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001631671</rptOwnerCik>
            <rptOwnerName>Ritter Andrew J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O GT BIOPHARMA, INC. 505 MONTGOMERY</rptOwnerStreet1>
            <rptOwnerStreet2>STREET, 9TH AND 10TH FLOORS</rptOwnerStreet2>
            <rptOwnerCity>SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94111</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <ownerSignature>
        <signatureName>/s/ Andrew J. Ritter</signatureName>
        <signatureDate>2025-05-29</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
