U-29 may refer to one of the following German submarines:
- SM U-29 (Germany), was a Type U 27 submarine launched in 1913 and that served in the First World War until sunk by HMS Dreadnought on 18 March 1915, the only submarine to be sunken by a battleship
- During the First World War, Germany also had these submarines with similar names:
- SM UB-29, a Type UB II submarine launched in 1916 and sunk on 13 December 1916
- SM UC-29, a Type UC II submarine launched in 1916 and sunk on 7 June 1917
- During the First World War, Germany also had these submarines with similar names:
- German submarine U-29 (1936), a Type VIIA submarine that served in the Second World War until scuttled on 4 May 1945
- German submarine U-29 (S178), a Type 206 submarine of the Bundesmarine that was launched in 1974 and decommissioned in 2004
U-29 or U-XXIX may also refer to:
- SM U-29 (Austria-Hungary), a U-27-class submarine of the Austro-Hungarian Navy
  | 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. |