German submarine U-103 (1940)

U-103 was a Type IXB U-boat of Nazi Germany's Kriegsmarine during World War II. She was laid down on 15 November 1939 by the DeSchiMAG AG Weser yard in Bremen as yard number 967, launched on 1 June 1940 and commissioned on 24 August 1940 under the command of Kapitänleutnant Viktor Schütze.

U-103 conducted ten war patrols, primarily in the North Atlantic, sinking 45 ships for a total of 218,610 gross register tons (GRT) and damaging four more for a total of 29,061 GRT. She also damaged one warship, the British light cruiser HMS Nigeria.

Schütze was relieved by Kapitänleutnant Werner Winter on 1 August 1941. Winter was then replaced by Kapitänleutnant Gustav-Adolf Janssen on 1 March 1942. Janssen surrendered the boat after its final patrol to American forces on 19 May 1945, near Cuxhaven.

U-103 was transferred to Lisahally, Northern Ireland on 30 June 1945 as part of Operation Deadlight. She was sunk on 18 December 1945, in position 55°50′N 08°40′W.