The 40th Air Refueling Squadron is an inactive United States Air Force unit. It was last assigned to the 310th Strategic Aerospace Wing at Schilling Air Force Base, Kansas, where it was inactivated on 15 March 1963. The squadron's first predecessor is the 540th Bombardment Squadron, which served as a heavy bomber training unit during World War II until inactivating in a 1944 reorganization of Army Air Forces training units. The 40th Squadron was activated at Schilling in 1952 and performed worldwide refueling missions until inactivated.