German submarine U-191 was a Type IXC/40 U-boat of the Nazi German Kriegsmarine built for service during World War II. She was ordered on 4 November 1940 from AG Weser Bremen, laid down on 2 November 1941, and launched on 3 July 1942. She was commissioned under Kapitänleutnant Helmut Fiehn on 20 October 1942 and underwent crew training and work-ups until 31 March 1943.