German submarine U-1021 was a Type VIIC/41 U-boat of the German Navy (Kriegsmarine) during World War II. Laid down on 6 May 1943 at the Blohm & Voss yard in Hamburg, the submarine was launched on 13 April 1944, and commissioned on 25 May 1944, under the command of Oberleutnant zur See William Holpert.