The squadron operated from Ark Royal for the next three years, initially on anti-submarine duties, but later as surface search and torpedo-attack aircraft.

The squadron went with Ark Royal to the Atlantic, and by April 1940 they were supporting Allied operations during the Norwegian campaign, where they bombed Vaernes airfield.

[1] In June 1941 the squadron left Ark Royal, and in November that year returned to Iceland aboard HMS Victorious.

Formidable and the squadron remained in the Mediterranean to provide support for the Allied landings at Sicily and Salerno.

The Wing attacked the oil refineries at Palembang, Sumatra in January 1945 as part of Operation Meridian, following this up with later strikes on the Sakashima Gunto islands.

As the war in the Pacific moved closer to Japan 820 Squadron was assigned to the 7th Carrier Air Group, and carried out a number of raids on Tokyo prior to VJ-Day.

[1] It was then assigned to HMS Invincible in early 1981; on 6 March 1981 the squadron suffered a tragedy when two of its aircraft had a mid-air collision, five of the eight crew members were killed.

With the later decommissioning of Ark Royal, the squadron joined HMS Illustrious and by 1996 was in the eastern Atlantic, followed by a round the world deployment in 1997.

[1] With Illustrious in refit from 1998, 820 Squadron operated out of RNAS Culdrose on anti-submarine training exercises, followed with periods embarked on ships of the Royal Fleet Auxiliary.

[1] Further training periods followed, as well as a Search and Rescue effort in October 2004 to aid the stricken Canadian submarine HMCS Chicoutimi, which had been disabled after suffering a fire and flooding off the west coast of Ireland.

During 2014, 820 NAS was temporarily assigned to the Commando Helicopter Force until the two main troop carrying squadrons fully convert to the Merlin HC.4.

[6] On 3 July 2017, a Merlin Mk.2 helicopter of 820 NAS became the first aircraft to land on HMS Queen Elizabeth, piloted by 26-year-old Lieutenant Luke Wraith from Yorkshire.

In September, five Merlins from 820 Squadron, two in the AEW configuration, embarked on HMS Queen Elizabeth for her "Operation FIREDRAKE" deployment in northern European waters.