"Knapp" steamed out of Eniwetok for the invasion of the Palau Islands on 30 August, screening five battleships and later rendezvousing with , , , and before their strikes at targets in the Palaus during the struggle to take Peleliu. During September, "Knapp" screened heavy ships making strikes at the Philippine Islands, and on 6 October she sailed from Ulithi for the air strikes on Okinawa and Formosa in preparation for the Leyte landings, and fired protective antiaircraft cover for her force during the Formosa air battle of 12–14 October. After guarding the retirement toward safety of , which had been struck by an aerial torpedo 13 October, she rejoined her force for air strikes on Luzon, and screened them during the Battle of Surigao Strait, one phase of the decisive Battle of Leyte Gulf. She returned to Ulithi on 30 October, and two days later headed back to the Philippines. After was damaged on 3 November by a submarine torpedo, "Knapp" guarded her withdrawal to safety. From November 1944 to January 1945, "Knapp" screened air strikes on Luzon, French Indochina, and cities on the China coast neutralizing Japanese bases in preparation for the Lingayen invasion. Escorting which was hit during an air attack on 21 January, "Knapp" arrived in Ulithi 24 January 1945 with the crippled carrier. Accomplishing her mission, the veteran destroyer sailed 30 January for the West Coast, arriving 20 February for overhaul.