German politician who was a leading member of the Social Democratic Party during the Weimar Republic and longtime minister of interior of Prussia (1920–26; 1930–32).

An activist trade union leader, Severing was a member of the German imperial Reichstag (parliament) from 1907 to 1912, of the postwar Weimar constituent assembly (1919), and, until the beginning of the National Socialist era, of both the Weimar Reichstag and the Prussian state diet. In 1919, as state commissioner for Westphalia, he directed the suppression of a communist insurrection in the Ruhr. Later, he served as interior minister in the second Weimar cabinet of Hermann Müller (1928–30). His most important work, however, was accomplished in the Prussian interior ministry, where he achieved the democratic reform of the state police force. With Prussian Premier Otto Braun, he devoted himself to preserving in Prussia, by far the largest state in Germany, a viable socialist enclave amid the general decay of German social democracy. Forcibly ousted with his ministerial colleagues from his post by German Chancellor Franz von Papen in July 1932, he subsequently withdrew from the politics of National Socialist Germany but later resumed political activity after the fall of the Nazis in 1945.