German submarine U-38

U-38 may refer to one of the following German submarines:


 * SMU U-38, was a Type U 31 submarine launched in 1914 and that served in the First World War until surrendered on 23 February 1919
 * During the First World War, Germany also had these submarines with similar names:
 * SMU UB-38, a Type UB II submarine launched in 1916 and sunk on 8 February 1918; in 2008 UB-38's wreck was moved to reduce the danger to shipping
 * SMU UC-38, a Type UC II submarine launched in 1916 and sunk 14 December 1917
 * GS U-38 (1938), a Type IX submarine that served in the Second World War until scuttled on 5 May 1945