Lambert St. Louis International Airport (IATA: STL, ICAO: KSTL, FAA LID: STL) is the primary airport for St. Louis, Missouri, United States and the surrounding area. It is the largest international airport in the state of Missouri.

The airport lies outside the St. Louis city limits in St. Louis County. Portions of the airport are located in the cities of Berkeley and Bridgeton. Lambert St. Louis International Airport serves over 88 non-stop national and international destinations. In 2008, 14.4 million passengers traveled through the airport.