German submarine U-165

U-165 may refer to one of the following German submarines:


 * SMU U-165, a Type Mittel U submarine launched in 1918; served in World War I until accidentally sunk on 18 November 1918 before surrendering; raised and stricken on 21 February 1919; broken up
 * GS U-165 (1941), a Type IXC submarine that served in World War II until sunk on 27 September 1942