German submarine U-1003 was a Type VIIC/41 U-boat of Nazi Germany's Kriegsmarine during World War II. She was ordered on 14 October 1941, and was laid down on 18 January 1943, at Blohm & Voss, Hamburg, as yard number 203. She was launched on 27 October 1943, and commissioned under the command of Oberleutnant zur See Werner Strübing on 9 December 1943.