The 1st Armoured Personnel Carrier Squadron (1 APC Sqn) 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.