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 Kriegsrohstoffabteilung (War Raw Materials Department – KRA) of 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.