515th may refer to:
515th Air Defense Group, disbanded United States Air Force (USAF) organization 515th Air Mobility Operations Wing (515 AMOW), part of Air Mobility Command, stationed at Hickam Air Force Base, Hawaii 515th Bombardment Squadron, inactive United States Air Force unit 515th Parachute Infantry Regiment (United States), Regiment of the US Army during the Second World War 515th Strategic Fighter Squadron, inactive United States Air Force unit
See also 515 (number) 515 (disambiguation) 515, the year 515 (DXV) of the Julian calendar 515 BC