German submarine U-133

U-133 may refer to one of the following German submarines:


 * SMU U-133, a Type U 127 submarine laid down during the First World War but unfinished at the end of the war; broken up incomplete 1919–20
 * During the First World War, Germany also had this submarine with a similar name:
 * SMU UB-133, a Type UB III submarine launched in 1918
 * GS U-133 (1941), a Type VIIC submarine that served in the Second World War until sunk 14 March 1942