The 904th Expeditionary Air Refueling Squadron is an inactive United States Air Force unit. It was last assigned to the 320th Bombardment Wing at Mather AFB, California, where it was inactivated on 30 September 1986. The 904th Air Refueling Squadron was activated at Mather AFB in 1959 and provided air refueling support for its wing's Boeing B-52 Stratofortresses and other USAF aircraft until it was inactivated in 1989. In 1985 the two squadrons were consolidated into a single unit.