'Iceberg Oolong' was a British air attack from the fleet carriers of the British Pacific Fleet, otherwise Task Force 57 under the tactical command of Vice Admiral Sir Bernard Rawlings, on targets of the Japanese-held island of Formosa (11/13 April 1945).

While the British ships were refuelling on 7 April after TF57’s first series of 'Iceberg' attacks on targets round Okinawa, the US fleet carrier Hancock was put out of action by the impact of a kamikaze aeroplane. It was believed that many of these special attack aircraft were operating from airfields in northern Formosa, so Admiral Raymond A. Spruance, commanding the 5^th Fleet, requested that TF57 should attack these bases. With his force scheduled for only one more attack on targets in the Sakishima-gunto, Rawlings readily accepted the assignment, which was less hazardous for the four British fleet carriers with their armoured flight decks than it would have been for the US carriers with their wooden flight decks.

The carriers were ready to launch their aircraft at dawn on 11 April, but bad weather the imposed a 24-hour delay. Even then the attacking aircraft, comprising 48 Grumman Avenger bombers supported by 40 Vought Corsair fighter-bombers, were somewhat hampered by low cloud over the target airfields. A few Corsair fighters did manage to find and attack the airfields, while the Avenger bombers attacked the port of Kiirun, inflicting severe damage on the docks, shipping, and a chemical plant. Later in the day the Avenger bombers did manage to find an airfield, cratering the runways while the fighters strafed aircraft on the ground and airfield installations.

These attacks encountered no Japanese air opposition on 12 April, but two Fairey Firefly warplanes located a formation of five Japanese bombers heading toward Okinawa and despatched four of them. That evening a Japanese attack was detected as it headed for the British ships, but the combat air patrol of Corsair and Grumman Hellcat fighters shot down four of the attackers, damaged about six and drove off the rest of the attackers before they could reach the ships.

The British attacks on Formosan targets were resumed on the following day in better weather, the scheduled replenishment being postponed by 24 hours so that the ships could continue to maintain pressure on the Formosan bases. Four kamikaze aircraft tried to attack TF57 immediately before dawn in the only such raid during 'Iceberg Oolong', but were driven off by the British ships' anti-aircraft fire.

This three-day undertaking was the most successful yet undertaken by the four British carriers during this phase of 'Iceberg', for in addition to damaging Japanese airfields, destroying aircraft on the ground, and interdicting road and rail traffic, the carrier air groups claimed 16 Japanese aircraft destroyed in the air, together with at least six more damaged, for the loss of one Avenger and one Corsair to anti-aircraft fire, one Hellcat in air combat, and two other aircraft in accidents.

On completion of these operations, TF57 withdrew to replenish before steaming to San Pedro Bay, Leyte, for rest and recuperation.