The Socialist Union of Mauritanian Muslims (Arabic: اتحاد الاشتراكيين المسلمين الموريتانيين, French: Union socialiste des musulmans mauritaniens, abbreviated USMM) was a political party in Mauritania.
[2] The party was based in the Adrar Region, and represented French military interests in the area.
[3] USMM supported the French plan of the Common Organization of Saharan Regions (OCRS) and wished that Mauritania would remain within the French Community.
[4][5] The party sought to compete with the banned Nahda party in the Adrar Region, and its charter had some common points with the moderate sectors of Nahda.
[3][6] At the time around the 1958 French constitutional referendum USMM had moved closer to the governing PRM.