Seattle–Tacoma International Airport (IATA: SEA, ICAO: KSEA) is the primary international airport serving the Seattle metropolitan area in Washington state, United States. Also known as Sea-Tac Airport, it is located in SeaTac, Washington, approximately 14 miles south of downtown Seattle and 18 miles north of Tacoma. The airport is owned and operated by the Port of Seattle.
SEA is the largest airport in the Pacific Northwest and serves as a major hub for Alaska Airlines and a focus city for Delta Air Lines. The airport opened on July 9, 1949, and has grown to become one of the busiest airports in the United States. In 2025, SEA served a record 52.7 million passengers, making it the ninth busiest U.S. airport by passenger volume.
The airport operates one main terminal with six concourses: Concourses A, B, C, and D in the main building, plus two satellite concourses (North Satellite and South Satellite) accessible via the Satellite Transit System train. SEA serves 37 airlines flying to 96 domestic destinations and 37 international destinations across North America, Europe, Asia, and the Middle East.
Alaska Airlines is the largest carrier at SEA, operating from all concourses with concentration on Concourses C and D. Delta Air Lines has a growing presence on Concourse A and the South Satellite. The airport is a key gateway between the United States and Asia-Pacific, with nonstop service to Tokyo, Seoul, Hong Kong, Taipei, Manila, Singapore, Beijing, Shanghai, and Chongqing. European destinations include London, Paris, Frankfurt, Amsterdam, Dublin, Reykjavik, Copenhagen, Helsinki, Istanbul, Rome, and Barcelona.