German submarine U-43 was a Type IXA U-boat of Nazi Germany's Kriegsmarine during World War II. The keel for U-43 was laid down in August 1938 at Bremen; she was launched in May 1939 and commissioned in August. Between November 1939 and July 1943, the U-boat conducted 14 combat patrols, sinking 21 merchant ships for a total of 117,036 gross register tons (GRT), damaging one ship of 10,350 GRT and another of 9,131 GRT - enough for it to be declared a total loss. U-43 was sunk on 30 July 1943 southwest of the Azores by a torpedo dropped by a United States Navy aircraft; all 55 hands were lost.