After shakedown along the west coast, Makassar Strait departed San Diego 6 June and steamed via Pearl Harbor to the Marshalls carrying replacement aircraft and passengers; thence, she transported military casualties to Pearl Harbor and the west coast where she arrived San Diego 13 July. During much of the next 2 months she trained carrier pilots off southern California. Between 25 September and 15 October she ferried 129 planes to Hawaii and to Manus, Admiralties. After returning to Pear Harbor 26 October with 70 damaged wildcats on board, she resumed pilot training operations out of Pearl Harbor.
During the next 3 months Makassar Strait rendered valuable service in the training of naval and marine aviators. Pilots from a dozen air groups and squadrons made more than 6,700 landings as she participated in combat air patrol and hunter-killer training exercises and night carrier operations, as well as defensive training against simulated bomb and torpedo attacks.
With Composite Squadron 97 embarked, Makassar Strait departed Pearl Harbor 29 January 1945 and steamed via Eniwetok for combat duty in the western Pacific. Assigned to TG 50.8, between 9 February and 8 April she protected logistics ships operating in support of the Fast Carrier Task Force during devastating airstrikes against enemy targets from the Bonins to the Ryukyus.
Assigned to a support carrier group 8 April, Makassar Strait began air operations in the intense fighting on Okinawa. During the next 4 weeks she launched scores of sorties against targets in the Ryukyus. Her planes provided close air support for American ground troops and struck with effective and devastating force against enemy gun emplacements, ground installations, and airfields as the Americans drove to capture Okinawa— one of the last bastions of the crumbling Japanese defenses. In addition, the escort carrier’s planes destroyed four enemy aircraft.
Makassar Strait transferred her air squadron to Shipley Bay (CVE-85) at Kerama Retto 7 May and departed later that day for Guam where she arrived the 11th. She now operated in the Marianas between Guam and Saipan providing refresher training for carrier pilots, until departing for Hawaii 19 July. Steaming via Kwajalein where she loaded 50 planes, she reached Pearl Harbor 29 July. There she embarked 387 military passengers and sailed 14 August for the United States.
Arriving San Diego 21 August, Makassar Strait had steamed more than 91,000 miles in support of the Allied victory in the Pacific. She continued to train carrier pilots during the next 2 months; by the end of October the total number of landings on her flight deck since her commissioning had surpassed 15,500.
Makassar Strait departed San Diego 4 November for “Magic Carpet” duty. Steaming via Pearl Harbor, she transported replacement troops to the Marshalls; and after embarking 1,092 veterans at Kwajalein, returned to San Diego 29 November. Between 4 December and 3 January 1946 she made a similar cruise to Guam and back, transporting 1,123 officers and men to the United States.
Departing San Diego 5 January, Makassar Strait steamed via San Francisco to Tacoma, Washington, where she arrived 12 January. Assigned to the 19th Fleet, she underwent deactivation and decommissioned 9 August 1946. She entered the Pacific Reserve Fleet at Tacoma; and, while berthed there, was reclassified CVU-91 on 12 June 1955. On 28 August 1958 the Secretary of the Navy authorized her to be used as target for destruction. Her name was struck from the Navy list 1 September 1958. In April 1961 while under tow to San Clemente Island, CA she ran aground on San Nicholas Island, and was then sold for breaking up in situ on 2 May 1961 buyer unknown.
Makassar Strait received two battle stars for World War II service.