Phoenix Sky Harbor International Airport (IATA: PHX, ICAO: KPHX, FAA LID: PHX), commonly referred to as Sky Harbor Airport or simply Sky Harbor, is a civil–military public airport 3 miles (2.6 nmi; 4.8 km) east of downtown Phoenix, in Maricopa County, Arizona, United States. It is Arizona’s largest and busiest airport, and among the largest commercial airports in the United States; in 2021, PHX was the 8th-busiest airport in the United States and 22nd-busiest in the world. The airport serves as a hub for American Airlines and a base for Southwest Airlines. American (including American Eagle operated by Skywest and Mesa) serve more passengers from PHX than any other carrier.