German submarine U-57 was a Type IIC U-boat of the Nazi German Kriegsmarine that served in the Second World War. She was built by Deutsche Werke AG in Kiel as 'werk' 256. Ordered on 17 June 1937, she was laid down on 14 September, launched on 3 September 1938 and commissioned on 29 December under the command of Oberleutnant Claus Korth.