German submarine U-670

German submarine U-670 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II. The submarine was laid down on 25 November 1941 at the Howaldtswerke yard at Hamburg, launched on 15 December 1942, and commissioned on 26 January 1943 under the command of Oberleutnant zur See Guido Hyronimus.

Attached to 5th U-boat Flotilla based at Kiel, U-670 collided during training in the Baltic Sea with the target ship Bolkoburg and sank. Of her crew of 43, 22 survived while 21 perished in the accident.