The Independent Social Democratic Party of Germany (German: Unabhängige Sozialdemokratische Partei Deutschlands, 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 anti-war members of the Social Democratic Party of Germany (SPD), from the left of the party as well as the centre and the right. The organization attempted to chart a course between electorally oriented reformism on the one hand and Bolshevist revolutionism on the other. The organization was terminated in 1931 through merger with the Socialist Workers' Party of Germany (SAPD).