Ronald Reagan Washington National Airport (IATA: DCA, ICAO: KDCA, FAA LID: DCA) is a public airport located three miles (5 km) south of the central business district of Washington, D.C., in Arlington County, Virginia, United States. It is notable for being the nearest commercial airport to Washington, D.C. Originally named Washington National Airport, the facility was renamed after former President Ronald Reagan in 1998. The airport is commonly known as "National", "Washington National", "Reagan", and "Reagan National"; "DCA" is used as the main airport code.

The airport is a focus city for US Airways, also the airport's largest carrier. The US Airways Shuttle offers air shuttle service to LaGuardia Airport in New York City and Logan International Airport in Boston, Massachusetts. Delta Air Lines' Delta Shuttle offers air shuttle service to LaGuardia Airport in New York City. With a handful of exceptions, flights are restricted to destinations within 1,250 miles (2,012 km), in an effort to control aviation noise and to drive air traffic to the larger but more distant Washington Dulles International Airport. In 2006, the airport served approximately 18.5 million passengers. Because the airport only provides U.S. immigration and customs facilities for corporate jet traffic, the only international flights allowed to land at DCA are those from airports with U.S. Customs and Border Protection preclearance, which include Nassau, Bahamas, Bermuda, Toronto, Ontario, and Montreal, Quebec.