The 1st Armoured Personnel Carrier Squadron was an armoured unit of the Australian Army raised for service during the Vietnam War. Raised in 1965, the unit was deployed to South Vietnam in May 1966 to join the 1st Australian Task Force. After that 1 APC Sqn was involved in numerous operations in support of the 5th and 6th Battalions, the Royal Australian Regiment, with the most notable action coming on 18 August 1966 when the squadron was involved in the Battle of Long Tan. In January 1967, 1 APC Sqn was redesignated as 'A' Squadron, 3rd Cavalry Regiment.

The 1st Australian Task Force was a brigade-sized formation which commanded Australian and New Zealand Army units deployed to South Vietnam between 1966 and 1972. 1 ATF was based in a rubber plantation at Nui Dat, 8 kilometres (5.0 mi) north of Bà Rịa in Phuoc Tuy Province and consisted of two and later three infantry battalions, with armour, aviation, engineers and artillery support. While the task force was primarily responsible for securing Phuoc Tuy Province, its units, and the Task Force Headquarters itself, occasionally deployed outside its Tactical Area of Responsibility.