German submarine U-170 was a Type IXC/40 U-boat of Nazi Germany's 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 yard number 709. She was launched on 6 June 1942 and commissioned on 19 January 1943 with Kapitänleutnant Günther Pfeffer in command.