German submarine U-203 was a German Type VIIC submarine U-boat built for Nazi Germany's Kriegsmarine for service during World War II. Built as yard number 632 of Friedrich Krupp Germaniawerft AG in Kiel, she was laid down on 28 March 1940, launched on 4 January 1941 and commissioned on 18 February under Kapitänleutnant Rolf Mützelburg. U-203 carried out eleven patrols with the first flotilla and is credited with sinking 21 ships for 94,270 gross register tons (GRT) and damaging a further three for 17,052 GRT. She was a member of eleven wolfpacks.