The Independent Social Democratic Party of Germany (, USPD) was a short-lived political party in Germany during the German Empire and the Weimar Republic. The organization was established in 1917 as the result of a split of left wing members of the Social Democratic Party of Germany (SPD). The organization attempted to chart a centrist course between electorally oriented revisionism on the one hand and bolshevism on the other. The organization was terminated in 1931 through merger with the Socialist Workers' Party of Germany (SAPD).