Roi is a small island in Kwajalein Atoll, taken on 1 February 1944. Kaiser at Vancouver laid the escort carrier down as Alava Bay on 22 March 1944, Maritime Commission hull 1140, and renamed her Roi on 26 April. She was launched on 2 June. Mrs. William Sinton sponsored her. Captain P. H. Lyon commissioned her on 6 July 1944.
After shakedown off San Diego she joined the Carrier Transport Squadron. On 13 August she sailed for Espiritu Santo and Manus with 287 passengers and 71 planes, and she was back at San Diego on 27 September. She sailed for Manus again on 21 October, returned, and on 2 December began a third voyage, to Eniwetok and Guam. After an overhaul at Alameda she made two more round trips to the Marshalls and the Marianas, then went to Pearl Harbor to refresh the ship for replenishment duty.
She loaded 61 replacement aircraft, already in a thirty-day combat-ready state, and reported at Guam to Task Group 30.8. On 4 July 1945 she sailed with Admiralty Islands (CVE-99), Hollandia (CVE-97), and Thetis Bay (CVE-90). They met Task Force 38 on 12 July, 16 July, and 20 July, and retired to Guam on the 21st to reload. She sailed again on the 27th with 61 more planes and joined the fast carriers on the 31st. Reloaded once more, she met the task force on 14 August, just before the fighting stopped, and stayed with the Third Fleet off Japan for the occupation.
She then brought veterans home. She was decommissioned at Bremerton on 9 May 1946, struck on 21 May, and sold on 31 December 1946 to Zidell Machinery and Supply Company of Portland, Oregon. She received one battle star.