Following commissioning, Ocean was sent to Cammell Laird at Birkenhead for modification to operate night fighters - changes included revised radar (with American SM-1 radar replacing the British Type 277 height-finding radar) and improved direction-finding equipment.
On completion of these changes in November 1945, Ocean was based at Rosyth for flying trials, with the first trials of the de Havilland Sea Hornet twin-engine fighter and the last carrier operations of the Fairey Swordfish biplane torpedo bomber.
On 3 December 1945, a Sea Vampire flown by Eric "Winkle" Brown made the first  ever carrier landing of a purely jet-powered aircraft onto Ocean (although earlier that year a composite jet and piston engined Ryan FR-1 Fireball had made a carrier landing under jet power after its radial engine failed.)
 
In December 1945, Ocean transferred to the Mediterranean Fleet, with an air group consisting of the Supermarine Seafire-equipped 805 Naval Air Squadron and 816 Naval Air Squadron, equipped with Fairey Firefly night fighters.
She disembarked her air group at Malta in June 1946 to allow her to be used as a troopship to carry troops to Singapore.
In October 1946 she provided fire-fighting and medical support to the two destroyers Saumarez and HMS Volage (R41) when they struck mines in the Corfu Channel incident.
In May 1948, she formed part of the task force supporting the withdrawal of British forces withdrew from Palestine, providing air cover after RAF bases in Palestine had been evacuated.

Ocean twice deployed to Korea, firstly from May to October 1952 and then from May to November 1953.
In August 1952 a formation of Hawker Sea Fury aircraft from the carrier engaged North Korean MiG-15 jets in air combat, shooting one down.

In August 1954 she joined the Home Fleet's training squadron but saw an active role in the Suez crisis.
In the first ever large-scale helicopter borne assault, Westland Whirlwind and Bristol Sycamore helicopters from Ocean and HMS Theseus landed 425 men of 45 Commando and 23 tons of stores into Port Said in 90 minutes.
After Suez, the ship did not see much more active service.
In September 1957, the Soviet Union protested when HMS Maidstone accompanied Ocean on a visit to Helsinki.
She went into extended reserve in 1958 and was scrapped in 1962 at Faslane.

In his book on the Hungarian Revolution, Peter Fryer briefly refers to the "arrest of twelve British seamen in the aircraft carrier Ocean, following unlawful meetings" in October 1956.
Following commissioning, Ocean was sent to Cammell Laird at Birkenhead for modification to operate night fighters - changes included revised radar (with American SM-1 radar replacing the British Type 277 height-finding radar) and improved direction-finding equipment. On completion of these changes in November 1945, Ocean was based at Rosyth for flying trials, with the first trials of the de Havilland Sea Hornet twin-engine fighter and the last carrier operations of the Fairey Swordfish biplane torpedo bomber. On 3 December 1945, a Sea Vampire flown by Eric "Winkle" Brown made the first  ever carrier landing of a purely jet-powered aircraft onto Ocean (although earlier that year a composite jet and piston engined Ryan FR-1 Fireball had made a carrier landing under jet power after its radial engine failed.)  
In December 1945, Ocean transferred to the Mediterranean Fleet, with an air group consisting of the Supermarine Seafire-equipped 805 Naval Air Squadron and 816 Naval Air Squadron, equipped with Fairey Firefly night fighters. She disembarked her air group at Malta in June 1946 to allow her to be used as a troopship to carry troops to Singapore. In October 1946 she provided fire-fighting and medical support to the two destroyers Saumarez and HMS Volage (R41) when they struck mines in the Corfu Channel incident. In May 1948, she formed part of the task force supporting the withdrawal of British forces withdrew from Palestine, providing air cover after RAF bases in Palestine had been evacuated.
Ocean twice deployed to Korea, firstly from May to October 1952 and then from May to November 1953. In August 1952 a formation of Hawker Sea Fury aircraft from the carrier engaged North Korean MiG-15 jets in air combat, shooting one down.
In August 1954 she joined the Home Fleet's training squadron but saw an active role in the Suez crisis. In the first ever large-scale helicopter borne assault, Westland Whirlwind and Bristol Sycamore helicopters from Ocean and HMS Theseus landed 425 men of 45 Commando and 23 tons of stores into Port Said in 90 minutes. After Suez, the ship did not see much more active service. In September 1957, the Soviet Union protested when HMS Maidstone accompanied Ocean on a visit to Helsinki. She went into extended reserve in 1958 and was scrapped in 1962 at Faslane.
In his book on the Hungarian Revolution, Peter Fryer briefly refers to the "arrest of twelve British seamen in the aircraft carrier Ocean, following unlawful meetings" in October 1956.
HMS Ocean (R68)