The squadron was formed at RAAF Station Pearce, Western Australia, in March 1942 and saw action in the South West Pacific theatre of World War II, operating Curtis P-40 Kittyhawks.

The squadron was about to return to Australia when the Korean War broke out in June 1950, after which it joined United Nations forces supporting South Korea.

It converted from Mustangs to Gloster Meteor jets between April and July 1951 and remained in Korea until October 1954, claiming five MiG-15s and over five thousand buildings and vehicles destroyed during the war for the loss of almost sixty aircraft, mainly to ground fire.

[8][9] Capable of 9G manoeuvres, the single-seat, single-engined F-35 is armed with a 25 mm cannon and can carry short- and medium-range air-to-air missiles and guided air-to-surface ordnance in an internal weapons bay.

77 Squadron saw action defending Darwin from Japanese air raids and claimed its first aerial victory just after 5 a.m. on 23 November 1942, when Cresswell destroyed a Mitsubishi "Betty" bomber.

77 Squadron registered its first daytime victory on 11 April, when a Kittyhawk shot down a Mitsubishi Zero taking part in a raid on Allied shipping near Buna.

[14][27] By this time, Allied headquarters had finalised plans for a drive north to the Philippines involving heavy attacks on Rabaul and the occupation of territory in New Guinea, New Britain and the Solomon Islands.

[29] As Japanese fighter opposition was limited, the squadron took part in several ground-attack missions in New Britain, armed with incendiary and general-purpose bombs, a practice that had been employed by Kittyhawk units in the Middle East.

[29][30] During one such raid on 2 August, Cresswell's designated successor as commanding officer, Flight Lieutenant Daryl Sproule, was forced to crash-land on a beach and was captured and executed by the Japanese.

[36] Their primary duty was providing air cover for Allied shipping, though no Japanese aircraft were encountered; they also flew ground-attack missions in support of US troops on Manus Island.

[46] Occupation duties proved uneventful, the main operational task being surveillance patrols, but units maintained an intensive training regime and undertook combined exercises with other Allied forces.

[50] The squadron was now the largest operational unit in the RAAF, with a strength of 299 officers and men, forty Mustangs, three CAC Wirraways, two Douglas C-47 Dakotas and two Austers.

[56] The Australian unit was specifically requested by General Douglas MacArthur, commander of UN forces; the Mustang was considered the best long-range ground-attack aircraft in the theatre, and Stratemeyer contended that No.

77 Squadron attacked a train full of US and South Korean troops on the main highway between Suwon and Pyongtaek, inflicting many casualties, twenty-nine of them fatal.

[60][61] Spence had raised concerns before the mission that the North Koreans could not have penetrated so far south, but was assured by Fifth Air Force controllers that the target was correct; the incident was widely reported in US newspapers but a public statement by Stratemeyer cleared the RAAF of any blame.

To expedite turnaround times between missions, the Mustangs, which were still based at Iwakuni, often refuelled and rearmed at Taegu near the Pusan Perimeter, where UN forces made a last-ditch stand on the southern tip of Korea.

[67] According to the official history of the Air Force in 1946–71, the squadron's part in the victory at Pusan earned recognition "not only for the RAAF but also Australia at the highest political levels in the United States".

[67][68] That month, the squadron claimed thirty-five tanks, 212 other vehicles, eighteen railway engines or cars, and thirteen fuel or ammunition dumps destroyed.

The Australian government agreed to purchase Gloster Meteor straight-wing jet fighters from Britain as the only viable alternative; the initial order included thirty-six single-seat Mk.8 interceptors and four two-seat Mk.7 trainers.

[88][89] MiG-15s had appeared on several occasions without engaging the Meteors; it was speculated at the time, and subsequently confirmed, that they had been observing the performance of the newly arrived RAAF jets.

77 Squadron out of its air-to-air combat role and curtail its operations in "MiG Alley", the area between the Yalu and Chongchon Rivers on North Korea's border with Manchuria.

This caused controversy among those who believed that proper tactics exploiting the Meteor's manoeuvrability and heavy armament would have allowed it to remain competitive as a fighter; for the Australian pilots the change of role amounted to a loss of prestige.

Morale suffered and it was not until Wing Commander Ron Susans succeeded Steege on 26 December 1951 that the Meteors were once more assigned an offensive role, namely ground attack.

[134] The Butterworth-based Sabres, armed with Sidewinder missiles, were responsible for regional air defence during the Konfrontasi between Indonesia and Malaysia from July 1963 until August 1966, though no combat took place.

77 Squadron returned to Williamtown in early 1969 to re-equip with Dassault Mirage III supersonic fighters, undertaking its initial flights on 7 July.

[147][148] The transfer swelled the squadron's strength to fifty-six aircraft—forty Mirages and sixteen Macchis—and over 500 officers and men, making it the largest operational unit in the RAAF.

[158] In September that year, the squadron undertook a proving exercise over Halifax Bay in Far North Queensland, when four of its Hornets—refuelled in flight on the round trip from Williamtown by a Boeing 707 tanker—became the first jet aircraft in Australia to drop aerial mines.

77 Squadron were deployed to protect the US base at Diego Garcia in the Indian Ocean between November 2001 and February 2002, during the early phase of the war in Afghanistan.

[161] In March 2006, the squadron sent a detachment of aircraft to RAAF Base East Sale, Victoria, to assist with security for the Commonwealth Games being held in Melbourne.

77 Squadron deployed to the Middle East in October 2015 as part of Operation Okra, Australia's contribution to the war against the Islamic State; by the end of the year it had flown twenty-one strike missions over Syria.