Singapore Airlines is the flag carrier of Singapore with its hub located at Changi Airport, and a member of the Star Alliance. The airline is notable for highlighting the Singapore Girl as its central figure in the corporate branding segment as well as not significantly changing its livery throughout its history. Widely renowned as one of the world's best carriers, the airline is ranked as a 5-star airline by Skytrax, and it has also been ranked as the world's best airline five times. The airline operates a variety of Airbus and Boeing aircraft, namely the A350, A380, Boeing 737, Boeing 747 Freighter, Boeing 777 and Boeing 787.

An airline hub or hub airport is an airport used by one or more airlines to concentrate passenger traffic and flight operations. Hubs serve as transfer points to help get passengers to their final destination. It is part of the hub-and-spoke system. An airline may operate flights from several non-hub (spoke) cities to the hub airport, and passengers traveling between spoke cities connect through the hub. This paradigm creates economies of scale that allow an airline to serve city-pairs that could otherwise not be economically served on a non-stop basis. This system contrasts with the point-to-point model, in which there are no hubs and nonstop flights are instead offered between spoke cities. Hub airports also serve origin and destination (O&D) traffic.