Joseph Koeth (7 July 1870 – 22 May 1936) was a German military officer and politician. During World War I he served as head of the commodity office in the Prussian Ministry of War created by Walther Rathenau. After the German revolution of 1918, Koeth was in charge of economic demobilisation as a member of the first democratically elected government under Philipp Scheidemann. He again served briefly as a minister of the Weimar Republic under Gustav Stresemann in 1923.