She arrived at Espiritu Santo on 19 March and began loading cargo the next day for the Army's 27th Division in preparation for the Ryukyus campaign. "Whiteside" steamed out of Segond Channel on 25 March bound — via Ulithi — for Okinawa. The attack cargo ship arrived in the Ryukyus on 9 April, eight days after the landings. She remained there a week conducting unloading operations that were frequently interrupted by enemy air raids. During her stay off Okinawa, "Whiteside" engaged two of the hordes of attacking aircraft, but claimed no kills.