Washington Dulles International Airport (IATA: IAD, ICAO: KIAD) is a public airport located 25 miles (40 km) west of the central business district of Washington, D.C., in Dulles, Virginia. It serves the greater Washington, D.C. metropolitan area.

Washington Dulles airport ranked 29th in 2006 in traffic movements. In 2007, Dulles saw 24.7 million passengers through the airport.

The airport occupies approximately 11,000 acres (17.19 mi²/ 44.5 km²) of land 26 miles (41.8 km) west of downtown Washington, straddling the border of Fairfax County and Loudoun County, Virginia. It is located partly in Chantilly and partly in Dulles, west of Herndon and southwest of Sterling. In 1958, the village of Willard was torn down to make room for Dulles, and countless roads, homes, stores, and schools were demolished to make room for runways, concourses and other features.