List of Australian Army units

In March 1901, the Australian Army came into existence as the Commonwealth Military Forces through the amalgamation of the former colonies military forces. The existing regiments and battalions of the colonies were reorganised and renumbered due to their absorption into the national army and subsequently formed the first military units of a united Australia. At the outbreak of World War I, in July 1914, the Australian Government committed the First Australian Imperial Force (AIF), a fully volunteer force, to the war; all existing units were exempt from serving overseas due the Defence Act of 1903, which stipulated that they could only serve in Australian territory.

In 1921, the Citizens Force's regimental numbering system, used since federation, was replaced by a divisional structure when the Australian Government decided to continue the unit designations of the AIF and to continue the traditions of the units of World War I. This renumbering brought about the end of localised regiments, with battalions taking up their role as community recruitment organisations.

In 1939, following the start of World War II the Australian Government created the Second Australian Imperial Force which would see combat in North Africa and the Pacific.

This list covers individual units, above or equivalent to a battalion, which were created or maintained after 1901, by either being militia units that were amalgamated and/or renumbered or being entirely new entities.

The field army has been the largest ever created unit for the Australian Army and has only been utilised in the Second World War.

In the history of the Australian Army, only during the world wars were tactical corps units raised.