721 Naval Air Squadron formed up at RNAS Belfast (HMS Gadwall) on 1 March 1945 as a Fleet Requirements Unit for operations in the Pacific.

Here, part of 721 Naval Air Squadron began working with RN Mobile Malaria Hygiene Unit No.

[4] Three Vultee Vengeance TT.IVs, supplied by the Royal Australian Air Force (RAAF), were fitted for spraying the insecticide DDT.

The following month the squadron's 'B' Flight embarked in the Colossus-class aircraft carrier, HMS Glory for a period of time and notably this was the last FAA unit to operate Vought Corsair.

[2] On 27 August the squadron took over six Supermarine Sea Otter, an amphibious air-sea rescue aircraft and another RAAF de Havilland Tiger Moth, a biplane trainer aircraft, from the disbanding 1701 Naval Air Squadron and these form an air-sea rescue (ASR) flight.