The 573d Tactical Air Support Squadron is an inactive United States Air Force unit. It was formed by the consolidation of two earlier units bearing the number 573, but has not been active since the consolidation. The squadron's second predecessor is the 573d Fighter-Day Squadron, which formed part of the 342d Fighter-Day Wing, when the Air Force reopened Myrtle Beach Air Force Base. A few months after it was activated, the squadron transferred its personnel and equipment to another squadron and was inactivated. The two squadrons were consolidated in 1985.