She was the only ship named for Commodore Frank H. Newcomb of the United States Revenue Cutter Service, Congressional Gold Medal recipient from the Spanish–American War.

As flagship of Destroyer Squadron 56 (DesRon 56), Newcomb joined in the Leyte landings 12 October to 4 December, covering underwater demolition teams and firing preinvasion-bombardment, call-fire, night-harassing and illumination missions.

In this battle, Newcomb and her sister ships played a key role in the victory which insured the success of General Douglas MacArthur's return to the Philippines, and effectively ended major Japanese naval threats for the remainder of the war.

With the effort that won them a Navy Unit Commendation, her crew worked furiously to repair engine damage and extinguish fires, while continuing to fight their ship and maneuver to avoid further crashes.

Repairs to her hull were made by Vestal under frequent enemy air attack, and on 14 June she left under tow for Saipan, Pearl Harbor, and San Francisco, arriving 8 August.