German submarine U-855

German submarine U-855 was a Type IXC/40 U-boat built for Nazi Germany's Kriegsmarine during World War II.

U-855 was ordered in June 1941 from DeSchiMAG AG Weser in Bremen under the yard number 710. Her keel was laid down on 21 October 1942 and the U-boat was launched the following year on 17 April 1943. She was commissioned into service under the command of Kapitänleutnant Albert Sürenhagen (Crew 36) in 4th U-boat Flotilla.

In April 1944 Sürenhagen handed over command to Oberleutnant zur See Prosper Ohlsen (Crew 36). U-855 transferred to the 10th U-boat Flotilla for front-line service and left Kiel for operations in the North Atlantic on 22 June 1944, but experienced engine problems which forced her to return to Kiel. The U-boat left Kiel again on 1 July and served as a weather boat in the North Atlantic until September 1944.

An attack on an unescorted freighter on 6 September 1944 was not successful. The next day U-855 met with GS 516 and supplied her with provisions for twelve days. The following day, 9 September, she refuelled U-516 before making for port. Her last transmission was received on 11 September 1944, after that the U-boat was missing.

Since U-855 would have had to pass through known mine barrages about a week into her return voyage. Since she failed to report the successful passage, as other U-boats would do, she was probably sunk by a mine on 17 October. That day another U-boat in the vicinity, GS U-804 reported hearing an explosion of a mine. The previous assumption that U-855 was attacked and sunk by a British aircraft, Liberator 'A' of No. 224 Squadron RAF, on 24 September is not correct as this attack damaged GS U-763.