History

The Order of Australia was instituted 14 February 1975 by letters patent of Queen Elizabeth II on the advice of Australian Prime Minister Gough Whitlam. The Order is conferred upon members of the Australian community who have rendered outstanding service to the nation. Prior to the establishment of this Order, Australian citizens were recognised within the British honour system.

The Order originally had 3 grades, Companion (AC), Officer (AO) and Member (AM), as well as two divisions, Civil and Military. The insignia for both the Civil and Military division is the head of a single Mimosa flower. Affixed to the top of the flower, is a crown that increases in detail as the grade increases.The insignia is suspended from a royal blue ribbon that features a central band with yellow mimosa flowers. Unlike the ribbon for the Civil Division, the Military Division ribbon has 1.5 mm wide yellow edges.

The Order currently consists of three grades and a medal, Companion, Officer, Member, and Medal of the Order of Australia.

Officers of the Order are issued a silver gilt neck badge and are entitled to use the post-nominal letters AO.