German submarine U-115

U-115 may refer to one of the following German submarines:


 * SMU U-115, the lead ship of the Type U 115 submarines; laid down during the First World War; unfinished at the end of the war; broken up incomplete; diesel engines used in SMS Gefion
 * During the First World War, Germany also had this submarine with a similar name:
 * SMU UB-115, a Type UB III submarine ordered in 1917 and sunk 29 September 1918
 * GS U-115 (1939), would have been a Type XIB submarine, a large cruiser submarine capable of carrying an Arado Ar 231 aircraft; laid down in 1939, but cancelled after the outbreak of the Second World War