Qantas is the flag carrier of Australia and its largest airline by fleet size, international flights and international destinations.

It is the world's third-oldest airline still in operation, having been founded in November 1920; it began international passenger flights in May 1935.

Qantas is an acronym of the airline's original name, Queensland and Northern Territory Aerial Services, as it originally served Queensland and the Northern Territory, and is popularly nicknamed "The Flying Kangaroo". Qantas is a founding member of the Oneworld airline alliance.

The airline is based in the Sydney suburb of Mascot, adjacent to its main hub at Sydney Airport.

Qantas also owns Jetstar, a low-cost airline that operates both international services from Australia and domestic services within Australia and New Zealand; and holds stakes in a number of other Jetstar-branded airlines.