U-24 may refer to one of the following German submarines:
- SM U-24, was a Type U 23 submarine launched in 1913 and that served in the First World War until surrendered on 22 November 1918
- During the First World War, Germany also had these submarines with similar names:
- SM UB-24, a Type UB II submarine launched in 1915 and surrendered on 24 November 1918
- SM UC-24, a Type UC II submarine launched in 1916 and sunk on 24 May 1917
- During the First World War, Germany also had these submarines with similar names:
- German submarine U-24 (1936), a Type IIB submarine that served in the Second World War until scuttled on 25 August 1944
- German submarine U-24 (S173), a Type 206 submarine of the Bundesmarine that was launched in 1974 and was sold to Colombia after decommissioning on 31 March 2011 where she serves as ARC Indomable.
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.