U-53 may refer to one of the following German submarines:
- SM U-53, a Type U 51 submarine launched in 1916 and that served in the First World War until surrendered 1 December 1918; broken up at Swansea in 1922
- During the First World War, Germany also had these submarines with similar names:
- SM UB-53, a Type UB III submarine launched in 1917 and sunk on 3 August 1918
- SM UC-53, 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-53 (1939), a Type VIIB submarine that served in the Second World War until sunk on 23 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.