Flag of Australia

A blue field serves as the background for the Union Jack, which occupies the upper hoist quarter of the design. Directly beneath the canton sits a large seven-pointed star, while the fly half displays five white stars of varying sizes arranged to represent a constellation. The layout follows the 1:2 aspect ratio common to British ensigns.

Inclusion of the Union Jack in the canton acknowledges Australia's historical and constitutional ties to the United Kingdom. The seven-pointed Commonwealth Star symbolizes the federation of the six original states and the nation's internal and external territories. Representing the Southern Cross, the constellation in the fly signifies Australia's geographical position in the Southern Hemisphere. These symbols collectively commemorate the country's British heritage, its federal structure, and its unique location.

Following the federation of the Australian colonies, a global design competition was held in 1901 to select a national flag. The winning entry was first flown in Melbourne on September 3, 1901, though the Commonwealth Star originally featured only six points. In 1908, a seventh point was added to this star to represent the Territory of Papua and any future territories. The Flags Act 1953 later formalized the Blue Ensign as the official national flag, ending decades of concurrent use with the Red Ensign.