No. 77 Squadron is a Royal Australian Air Force (RAAF) squadron headquartered at RAAF Base Williamtown, New South Wales. It is controlled by No. 81 Wing, part of Air Combat Group, and equipped with Lockheed Martin F-35 Lightning II multi-role stealth fighters.

No. 81 Wing is responsible for operating the Lockheed Martin F-35 Lightning II multi-role fighters of the Royal Australian Air Force (RAAF). Headquartered at RAAF Base Williamtown, New South Wales, the wing comprises three combat units, Nos. 3 and 77 Squadrons based at Williamtown and No. 75 Squadron at RAAF Base Tindal, Northern Territory, as well as an operational conversion unit at Williamtown. No. 81 Wing headquarters oversees squadron training in air-to-air and air-to-ground tactics, and support for the Australian Army and Royal Australian Navy. Tasked with offensive and defensive counter-air operations, the Hornets have been deployed to Diego Garcia in 2001–02, when they provided local air defence, to Iraq in 2003, when they saw action flying fighter escort and close air support missions in concert with Coalition forces, and to the Middle East in 2015–16, when they undertook strike operations during the military intervention against ISIL. They have also been employed to patrol high-profile events in Australia, including the Commonwealth Games and visits by foreign dignitaries.