German submarine U-170 was a Type IXC/40 U-boat of the Nazi German Kriegsmarine built for service during World War II. Her keel was laid down on 21 May 1941 by the Deutsche Schiff- und Maschinenbau AG in Bremen as 'werk' 709. She was launched on 6 June 1942 and commissioned on 19 January 1943 with Kapitänleutnant Günther Pfeffer in command. The U-boat's service began with training as part of the 4th U-boat Flotilla. She then moved to the 10th flotilla on 1 June 1943 for operations. She was re-assigned to the 33rd flotilla on 1 November 1944.