3 RAR was initially formed on 20 October 1945 as the 67th Battalion. The Battalion was intended for occupation duties in Japan and was formed from volunteers from the 3rd, 6th, 7th and 11th Australian Divisions. The battalion was redesignated the 3rd Battalion of the Australian Regiment upon the Regiment's formation in November 1948. The 'Royal' prefix was appended in March 1949.