U-155 may refer to one of the following German submarines:
- SM U-155, a Type U 151 submarine launched in 1916; known as the merchant submarine Deutschland from launch; commissioned as U-155 on 19 February 1917; served in World War I until surrendered on 24 November 1918; used as an exhibition in London; broken up at Morecambe in 1922
- During World War I, Germany also had this submarine with a similar name:
- SM UB-155, a Type UB III submarine laid down but uncompleted at the end of the war; surrendered to France and became French submarine Jean Corre; broken up 1936
- During World War I, Germany also had this submarine with a similar name:
- German submarine U-155 (1941), a Type IXC submarine that served in World War II; taken to Loch Ryan on 30 June 1945; sunk on 21 December 1945 as a part of Operation Deadlight
This article includes a list of ships with the same or similar names. If an internal link for a specific ship led you here, you may wish to change the link to point directly to the intended ship article, if one exists.