The 3rd Brigade is a combined arms brigade of the Australian Army, principally made up of the 1st and 3rd Battalions of the Royal Australian Regiment. Initially raised in 1903 as part of the post-Federation Australian Army, it was removed from the order of battle in 1906 following the restructure of the field force. It was re-formed in 1914 for service during World War I, taking part in the fighting at Gallipoli and on the Western Front in Europe. During World War II the brigade was used in a defensive role before it was disbanded in 1944. It was re-raised in 1967 for service during the Vietnam War and later went on to provide the nucleus of the deployment to East Timor during the Australian-led intervention in 1999. The brigade is currently based at Lavarack Barracks in Townsville, Queensland.

1st Battalion, Royal Australian Regiment is a regular motorised infantry battalion of the Australian Army. 1 RAR was first formed as the 65th Australian Infantry Battalion of the 34th Brigade (Australia) on Balikpapan in 1945 and since then has been deployed on active service during the Korean War, the Malayan Emergency, the Vietnam War, Unified Task Force in Somalia, East Timor, Iraq War and Afghanistan. Additionally, the battalion has deployed on peacekeeping and other operations to a number of countries including Japan, Rifle Company Butterworth, Timor Leste, Solomon Islands, Tonga and the Philippines. 1 RAR remains one of the Australian Army's most readily deployed units sending individuals and detachments to domestic, regional and other enduring operations. The battalion is currently based in Coral Lines at Lavarack Barracks, Townsville, Queensland, where it forms part of the 3rd Brigade.