517th

517th may refer to:

517th Air Defense Group, disbanded United States Air Force organization 517th Airlift Squadron (517 AS), part of the 3d Wing at Elmendorf Air Force Base, Alaska 517th Parachute Infantry Regiment (United States) (517th PIR), separate infantry regiment of the United States Army 517th Parachute Regimental Combat Team (517th PRCT), one of the U.S. Army's first elite combat units 517th Strategic Fighter Squadron, inactive United States Air Force unit

See also 517 (number) 517, the year 517 (DXVII) of the Julian calendar 517 BC