In the US military, the Air National Guard (ANG), as part of the National Guard, is the organized militia of a particular US state and is a reserve component of the US Air Force (USAF), too. Each state, territory, and the District of Columbia has an Air National Guard. As Federally-organized militia, Air National Guard units are liable to activation by both the President of the United States and the governor of the state in which the ANG unit resides. The Air National Guard is part of the National Guard Bureau which administers both the Army National Guard and the Air National Guard.

The ANG is said to be a "reserve" force, of "part-time soldiers"; many ANG pilots work for commercial airlines. The ANG flies every type of aircraft in the USAF inventory, with the exceptions of the B-2 Spirit stealth bomber and the F-117 Nighthawk stealth fighter.

Many ANG pilots believe that they are more skilled than regular USAF pilots; this may be true as ANG pilots are more likely to have had combat experience during the Gulf War.

ANG pilots have flown on active duty continually since the Gulf War of 1991, patrolling Iraq's no-fly zones. Following the September 11, 2001 attacks, a North Dakota F-16 unit (the Happy Hooligans from Hector International Airport) was the first unit to fly air cover over Washington, D.C., for at the time they were undergoing flight training at Langley Air Force Base, Virginia.

ANG units saw extensive service in both WW II and the Korean War, when units were activated intact. Many ANG pilots also served in the Vietnam War, but as individuals attached to Air Force units.

The ANG motto is "Semper Paratis", which means "always ready". The logo is intended to symbolize the minuteman of the American Revolution.