San Francisco International Airport (IATA: SFO, ICAO: KSFO) is the primary international airport serving San Francisco and the surrounding Bay Area. Located approximately 14 miles south of downtown San Francisco, the airport sits primarily in an unincorporated area of San Mateo County on the San Francisco Peninsula, adjacent to San Francisco Bay. SFO is owned and operated by the City and County of San Francisco.
SFO has been operating at its current location since May 27, 1927, when it opened as Mills Field Municipal Airport. The City and County of San Francisco purchased the land in 1930, and the airport was renamed San Francisco Airport in 1931. It received its current name, San Francisco International Airport, shortly after World War II to reflect the growth of international air service.
SFO is a major hub for United Airlines and Alaska Airlines, and serves as a key gateway between the United States and destinations across Asia, Europe, and the Pacific. The airport is one of only three West Coast gateways—along with Los Angeles (LAX) and Seattle (SEA)—that play a strategic role in U.S. air networks by providing access to markets in Asia and the South Pacific. SFO is the only airport in the San Francisco CSA and Northern California with substantial levels of international service and connecting traffic.
In Fiscal Year 2025, SFO served 54,118,814 total passengers. International passengers accounted for a significant share, with Asia representing the largest international region served, followed by Europe, Canada, Latin America, Australia/Oceania, and the Middle East. The airport offers an average of 125 daily international departures, connecting the Bay Area to destinations worldwide.