The Special Air Service Regiment (SASR) is a Special Forces regiment modelled on the original British SAS and also drawing on the traditions of the Australian World War II 'Z' Special Force commando unit, as well as the Independent Companies which were active in the South Pacific during the same period. It is based at Campbell Barracks, Swanbourne, Perth, Western Australia and is a unit of the Royal Australian Infantry Corps, part of the Australian Defence Force. As with the British SAS, the regimental motto is 'Who dares wins'.

The SASR's participation in the Vietnam War began when 3 Squadron deployed as part of the 1st Australian Task Force (1 ATF) in April 1966. The SASR's role in Vietnam was to act as the 'eyes and the ears' of the Australian Task Force through conducting reconnaissance patrols throughout 1 ATF's area of responsibility. As in Borneo the SASR operated closely with the New Zealand SAS, with a New Zealand SAS troop being attached to each Australian Squadron.

SASR Squadrons rotated through Vietnam on one year long deployments until the last Squadron was withdrawn in October 1971. During its time in Vietnam the Regiment was extremely successful in the reconnaissance role. To their enemies members of the regiment were known as the 'phantoms of the jungle' due to their fieldcraft.

The Australian and New Zealand SAS killed at least 492 and as many as 598 and losing only two men killed in action and three fatalities from friendly fire. The last remaining Australian soldier who went missing in action in 1969 after falling into the jungle during a suspended rope extraction was found in August, 2008.

Australia's SASR also worked with U.S. SEAL Teams and U.S. Army Special Forces, and provided instructors to the LRRP School. Some members also served with the highly secret MACV-SOG Units.