It was formed at Bankstown, New South Wales, on 12 February 1941 and began flying operations on 1 July as part of the North African Campaign in Egypt and Libya.

451 Squadron was withdrawn for refitting in early January 1942 and spent the remainder of the year performing garrison duties in Syria.

The squadron returned to combat in April 1944 when, operating from bases in Corsica, it took part in the Italian Campaign and Allied invasion of Southern France until September.

From January to April 1945, it took part in the liberation of Europe by escorting Allied bomber units and conducting air strikes against German V-2 rocket sites and transportation targets.

Following the war, the squadron was deployed to Germany from September 1945 as part of the Allied occupation forces, but was disbanded on 21 January 1946 when the Australian Government dropped plans for a permanent Australian contribution to the occupation of Germany due to a shortage of volunteers for this duty.

[1] The squadron's personnel departed Sydney on 9 April on board the ocean liner Queen Mary and arrived in Egypt on 5 May.

As an army cooperation unit its main duties were photographic and tactical reconnaissance and artillery spotting.

From March the squadron also maintained a detachment at Cyprus to counter German reconnaissance flights over the island and in June it took over responsibility for providing air defence to Haifa.

[1][11] As there were more Army cooperation units in the Middle East than were required and the Australian Air Board would not agree to convert No.

The squadron was responsible for air defence of part of the Nile Delta and nearby convoys and in February it received a detachment of Supermarine Spitfire fighters for high-altitude interceptions.

219 Group RAF in March which complained about the squadron's lack of employment and appeared to condone the poor morale within the unit.

451 Squadron's only offensive action during the year was a raid against Crete on 23 July in which it contributed six Hurricanes to a force of Beaufighter heavy fighters and Baltimore bombers.

[14] The squadron's role was to support Allied operations in Italy and southern France by escorting bombers and conducting armed reconnaissance patrols.

451 Squadron's Spitfires were damaged when 25 German Ju 88 bombers raided the unit's base at Poretta airfield.

By the time the ground crew arrived at Naples on 23 October the headquarters of the Mediterranean Allied Air Forces had decided that there was no need for the squadron in Italy and recommended that it be returned to Australia.

451 Squadron was issued with Mark XVI Spitfires and based at RAF Hawkinge in Kent from 2 December 1944.

From 20 March 1945 the two squadrons were mainly focused on attacking German transportation targets after the V-2 campaign against the UK ended.

453 Squadrons would form a long-term Australian contribution to the occupation of Germany, insufficient RAAF personnel volunteered for this duty to make the deployment viable.