U-44 may refer to one of the following German submarines:
- SM U-44, was a Type U 43 submarine launched in 1914 and that served in the First World War until sunk on 12 August 1917
- During the First World War, Germany also had these submarines with similar names:
- SM UB-44, a Type UB II submarine launched in 1916 and disappeared after 4 August 1916
- SM UC-44, a Type UC II submarine launched in 1916 and sunk on 4 August 1917
- During the First World War, Germany also had these submarines with similar names:
- German submarine U-44 (1939), a Type IX submarine that served in the Second World War until sunk in March 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.