German submarine U-2

U-2 may refer to one of the following German submarines:


 * SMU U-2 (Germany), a unique submarine launched in 1908 that served in the First World War as a training submarine and was scrapped in 1919
 * During the First World War, Germany also had these submarines with similar names:
 * SMU UB-2, a Type UB I submarine launched in 1915 and scrapped in 1919
 * SMU UC-2, a Type UC I submarine launched in 1915 and sunk on 30 June 1915
 * GS U-2 (1935), a Type IIA submarine that served in the Second World War and was sunk on 8 April 1944
 * GS U-2 (1962), a Type 201 submarine of the Bundesmarine, launched in 1962
 * GS U-2 (1966), a Type 205 submarine of the Bundesmarine that was launched in 1966 and sold in 1993

U-2 or U-II may also refer to:
 * SMU U-2 (Austria-Hungary), a U-1 class Austro-Hungarian Navy submarine