Established in January 1940, at HMS Peregrine, the Royal Naval Air Station at Ford, the squadron was sent to Coastal Command to protect the Dunkirk evacuation.

In June 1940, the squadron joined HMS Illustrious, serving in the North Atlantic before moving to the Mediterranean Fleet in August and participated in the Taranto attack in November.

However, from mid-2001, the squadron decreased in size and disbanded in November, leaving behind a two-aircraft unit called HMS Gannet Search and Rescue Flight, which operated from Prestwick.

Subsequently, in the following month, the entire squadron embarked in the name ship of her class, HMS Illustrious, for missions in the North Atlantic, with further training activities taking place in Bermuda.

[5] In August the ship joined the Mediterranean Fleet and 819 Naval Air Squadron frequently alternated between the carrier and RNAS Dekheila (HMS Grebe), Egypt, which served as a shore base.

[5] On 10 January 1941, when HMS Illustrious was subjected to an attack that resulted in significant damage, the squadron experienced substantial losses in personnel and aircraft.

[4] Following the completion of shore-based preparations and a partial re-equipment with Fairey Swordfish II aircraft, the unit embarked on the name ship of her class of escort carrier, HMS Avenger, for trials in June 1942.

As the vessel participated in Russian convoys, additional Grumman Wildcat fighter aircraft were incorporated to provide defense against bombers originating from Norway.

[5] Notably, on 3 April, aircraft 'C', in conjunction with Grumman Avenger torpedo bombers from 846 Naval Air Squadron, was credited with the destruction of the German submarine U-288.

[5] 819 Naval Air Squadron was reestablished on 9 February 1971, at RNAS Culdrose (HMS Seahawk), Somerset, becoming the third operational unit equipped with the Westland Sea King HAS.1 anti-submarine helicopter.

Each Flight comprised a single helicopter, accompanied by both air and ground personnel, and was prepared to function autonomously from Type 22 Frigates or Royal Fleet Auxiliaries (RFAs).

[12] However, the utilisation of Prestwick as a shore base proved to be unsuccessful, leading to the transfer of the flights to 810 Naval Air Squadron at RNAS Culdrose in November 1994.