Athens International Airport Eleftherios Venizelos (IATA: ATH, ICAO: LGAV), commonly initialised as AIA, is the largest international airport in Greece, serving the city of Athens and region of Attica. It began operation on 28 March 2001 (in time for the 2004 Summer Olympics) and is the main base of Aegean Airlines, as well as other smaller Greek airlines. It replaced the old Ellinikon International Airport.

Athens International Airport is currently a member of Group 1 of Airports Council International (over 25 million passengers). As of 2023, it is the 18th-busiest airport in Europe and the busiest and largest in the Balkans.

The new Athens Int'l Airport covers a huge expanse of 16,000 acres (25.0 sq mi; 64.7 km2), making the facility among the largest in Europe and in the world in terms of land area.