U-71 may refer to one of the following German submarines:
- SM U-71, a Type UE I submarine launched in 1915 and that served in World War I until surrendered on 23 February 1919; broken up at Cherbourg in 1921
- During World War I, Germany also had these submarines with similar names:
- SM UB-71, a Type UB III submarine launched in 1917 and sunk on 21 April 1918
- SM UC-71, a Type UC II submarine launched in 1916 and sunk on 20 February 1919 on way to surrender
- During World War I, Germany also had these submarines with similar names:
- German submarine U-71, a Type VIIC submarine that served in World War II until scuttled on 2 May 1945
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.