U-116 may refer to one of the following German submarines:
German submarine U-116 was a Type XB minelaying U-boat of Nazi Germany's Kriegsmarine during World War II.
She was ordered on 31 January 1939 and laid down on 1 July at Friedrich Krupp Germaniawerft, Kiel, as yard number 615. She was launched on 3 May 1941 and commissioned under the command of Korvettenkapitän Werner von Schmidt on 26 July of that year.
After a period of training as part of the 2nd U-boat Flotilla, U-116 was assigned to the front-line as part of the 1st U-boat Flotilla on 1 February 1942. She sailed from Kiel on 4 April 1942, bound for Bergen, Norway, via Heligoland, and departed Bergen on 25 April, circling the British Isles before arriving at Lorient in occupied France, on 5 May.
U-116 sailed from Lorient on 16 May 1942 on a patrol to the mid-Atlantic lasting 25 days, arriving back at her homeport on 9 June, without any success.
U-116 was more successful on her third patrol which took her south to the coast of West Africa, attacking Convoy OS-33 south of the Azores on 12 July 1942. Soon after midnight she fired one torpedo at the 7,093 ton GRT merchant ship Cortona, causing some damage; although the ship was then sunk by U-201. Nine hours later U-116 fired two torpedoes into the 4,284 ton British merchant ship Shaftesbury, which sank in 15 minutes. The U-boat returned to Lorient on 23 August, after 58 days at sea.