On 2 January 1944, she departed Norfolk, Virginia for the Pacific, reaching Funafuti atoll 20 days later, and escorting troop ships thence to Milne Bay, New Guinea, where she put in 7 February. As part of the 7th Fleet the destroyer supported the consolidation of Saidor in late February and escorted LSTs from Cape Sudest, New Guinea, to Cape Gloucester, New Britain, and Los Negros in the Admiralty Islands. On 6 March, the LSTs made landings in Hayne Bay, Los Negros, while "Gillespie" patrolled from five to fifteen miles off the northeast coast. While acting as a call fire ship for Army forces in Seeadler Harbor, Manus Island, she bombarded the eastern tip of Pityilu Island on 14 March and until the 16th continued to support the Manus assault by bombarding installations and gun emplacements on Manus. On 24–25 March, "Gillespie" bombarded targets on Pityilu, Manus, and Rambutyo Islands, returning to Oro Bay, New Guinea, 26 March.