German submarine U-420

German submarine U-420 was a Type VIIC U-boat built for the Kriegsmarine for service during World War II. She was laid down in the Danziger Werft as 'Werk' 121, launched on 18 August 1942 and commissioned on 16 December the same year under Oberleutnant Peter Högqvist. She then joined the 8th U-boat Flotilla for training before transferring to the 11th flotilla for operations.

1st patrol
U-420's first patrol involved her leaving Kiel on 12 June 1943 and arriving at Lorient in occupied France on 16 July 1943, having hugged the Norwegian coast and sailed around the north of Scotland. She then crossed the Atlantic, but was attacked on 3 July by a Canadian B-24 Liberator. The boat was hit by a Fido homing torpedo which killed two men and wounded a third. The boat sustained enough damage to force the patrol to be cut short.

2nd patrol and loss
Following a short transit voyage from Lorient to Brest, U-420 set off on her second patrol on 9 October 1943. After 20 October, she was never heard from again.