U-54 may refer to one of the following German submarines:
- SM U-54, a Type U 51 submarine launched in 1916 and that served in the First World War until surrendered 24 November 1918; broken up at Taranto in May 1919
- During the First World War, Germany also had these submarines with similar names:
- SM UB-54, a Type UB III submarine launched in 1917 and disappeared after 1 March 1918
- SM UC-54, a Type UC II submarine launched in 1916 and scuttled on 28 October 1918
- During the First World War, Germany also had these submarines with similar names:
- German submarine U-54 (1939), a Type VIIB submarine that served in the Second World War until she went missing after 20 February 1940
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.