Philadelphia International Airport (IATA: PHL, ICAO: KPHL, FAA LID: PHL) is the primary airport serving Philadelphia, Pennsylvania, United States. It served 12.4 million passengers annually in 2022, making it the busiest airport in Pennsylvania and the 21st-busiest airport in the United States. The airport is located 7 miles (11 km) from the city's downtown area and has 22 airlines that offer nearly 500 daily departures to more than 130 destinations worldwide.

The airport is the fifth-largest hub for American Airlines and serves as American Airlines' primary hub in the Northeastern United States and its primary European and transatlantic gateway. The airport is a regional cargo hub for UPS Airlines and a focus city for Frontier Airlines. The airport has service to cities in the United States, Canada, the Caribbean, Europe, Latin America, and the Middle East. As of 2019, the airport offers flights to 140 destinations, 102 of which are domestic and 38 of which international.

Much of the airport property is in the city of Philadelphia. Terminal A, the international terminal, and the western and southern ends of the airfield, are in Tinicum Township, Delaware County. PHL covers 2,302 acres (932 ha) and has four runways.