Singapore Changi Airport, commonly known as Changi Airport (IATA: SIN, ICAO: WSSS), is a major civilian airport that serves Singapore, and is one of the largest transportation hubs in Asia. Singapore's International Airport at Paya Lebar, Singapore's third main civilian airport after Seletar Airport (main airport from 1930 to 1937) and Kallang Airport (1937–55) opened in 1955 with a single runway and a small passenger terminal. With the growth in global aviation transport, the airport was facing congestion problems. Its inability to cope with the rising traffic became critical by the 1970s; annual passenger numbers rose dramatically from 300,000 in 1955 to 1.7 million in 1970 and to 4 million in 1975. Also the government subsequently decided in 1975 to build a new airport at the eastern tip of the main island at Changi, at the existing site of Changi Air Base, where the new airport would be easily expandable through land reclamation.
Today It is currently rated the World's Best Airport by Skytrax, for the seventh consecutive year since 2013. It is also the first Airport in the world to do so for seven consecutive years and is one of the world's busiest airports by international passenger and cargo traffic. The airport is located in Changi, at the eastern end of Singapore, approximately 20 kilometres northeast from Marina Bay (Singapore's Downtown Core), on a 13-square-kilometre site. It is operated by Changi Airport Group and it is the home base of Singapore Airlines, Singapore Airlines Cargo, SilkAir, Scoot, Jetstar Asia Airways and BOC Aviation.
In 2018, Changi served 65,628,000 passengers, making it the 19th busiest airport in the world in terms of passenger traffic.