Southwest Florida International Airport (IATA: RSW, ICAO: KRSW, FAA LID: RSW) is a major county-owned airport in the South Fort Myers area of unincorporated Lee County, Florida, United States. The airport serves the Southwest Florida region, including the Cape Coral-Fort Myers, Naples-Marco Island, and Punta Gorda metropolitan areas, and is a U.S. Customs and Border Protection port of entry. It currently is the second-busiest single-runway airport in the United States, after San Diego International Airport, California. In 2022, the airport served 10,343,802 passengers, the most in its history.

The airport sits on 13,555 acres (5,486 ha, 21.2 sq.mi.) of land just southeast of Fort Myers, making it the third-largest airport in the United States in terms of land size (after Denver and Dallas/Fort Worth). 6,000 acres of the land has been conserved as swamp lands and set aside for environmental mitigation.