Through the summer of 1944, the destroyer continued patrolling and training exercises off New Guinea and the Solomon Islands, and was on hand from 15 September to 14 October for screening activities during the amphibious assault on Peleliu in the Palau Islands. "Gillespie" sailed 14 October 1944 for overhaul at Bremerton, Washington, mooring there 5 November, and after refresher training, sailed from San Diego 3 January 1945. She conducted training exercises at Pearl Harbor and closed Ulithi 8 February, and subsequently as part of the Logistic Support Forces she escorted supply ships and units of the 5th Fleet during the seizure of Iwo Jima.