U-143 may refer to one of the following German submarines:
- SM U-143, a Type U 142 submarine laid down during the First World War but 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-143, a Type UB III submarine launched in 1918 and surrendered on 1 December 1918; served as Japanese submarine O-7, 1920–21; broken up at Yokosuka Navy Yard by June 1921; used as a floating jetty at Yokosuka after February 1924
- During the First World War, Germany also had this submarine with a similar name:
- German submarine U-143 (1940), a Type IID submarine that served in the Second World War; taken to Loch Ryan on 30 June 1945; sunk on 22 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.