German submarine U-756 was a Type VIIC U-boat built for the German Kriegsmarine for service during World War II. Launched from Werk 139 at the Kriegsmarinewerft (KMW) in Wilhelmshaven Lower Saxony (then, the Free State of Oldenburg), she served with 6th U-boat flotilla from December 30th, 1941 to September 1st, 1942 under the command of Kapitänleutnant Klaus Harney. U-756 did not survive to complete her first patrol and did not sink or damage any ships.