The flag of Australia is based on the British Blue Ensign—a blue field with the Union Jack in the upper hoist quarter—augmented with a large white seven-pointed star and a representation of the Southern Cross constellation, made up of five white stars. Australia also has a number of other official flags representing its people and government bodies.

The 1901 Federal Flag Design Competition was an Australian government initiative announced by Prime Minister Edmund Barton to find a flag for the newly federated Commonwealth of Australia. In terms of its essential elements the winning entries are the official flag of Australia.