U-127 may refer to one of the following German submarines:
- SM U-127, the lead ship of the Type U 127 submarines; laid down during the First World War; unfinished at the end of the war; broken up incomplete, 1919–20
- During the First World War, Germany also had this submarine with a similar name:
- SM UB-127, a Type UB III submarine launched in 1918 and sunk in September 1918
- During the First World War, Germany also had this submarine with a similar name:
- German submarine U-127 (1941), a Type IXC submarine that served in the Second World War until sunk on 15 December 1941
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.