Shannon Airport (Irish: Aerfort na Sionainne) (IATA: SNN, ICAO: EINN) is an international airport located in County Clare in Ireland. It is adjacent to the Shannon Estuary and lies halfway between Ennis and Limerick. With over 1.5 million passengers in 2022, the airport is the third busiest airport in the Republic of Ireland, and the fifth busiest on the island.

The airport was built in the late 1930s, with the first commercial flight taking place in 1939. Shannon was the landing point for the first transatlantic proving flight in 1945 and became the world's first duty-free airport in 1947. By the 1960s, it was a busy refuelling stop for many transatlantic carriers. Europe's first United States border preclearance facility opened in 1986. At 3.2 kilometres (2 mi), Shannon has the longest runway in Ireland, which allowed it to be a designated alternative landing site for the Space Shuttle.