Welles and her traveling companions arrived at Funafuti in the Ellice Islands on 21 January and remained there for a week before getting underway for New Guinea.

On 29 February, Welles provided gunfire support for elements of the Army's 1st Cavalry Division then landing on Los Negros Island in the Admiralties.

In March, she returned south to the area around Buna to prepare for operations to capture the remainder of the northern coast of New Guinea.

From there, the warship continued with General Douglas MacArthur's amphibious jump to Biak Island where she provided gunfire support during the landings and consolidation operations from 27 May to 2 June.

During that time, she destroyed several Japanese barges, harassed enemy ground forces, silenced a shore battery or two and helped to repel several air attacks.

She moved into Leyte Gulf on 18 October, two days before the actual landings, to cover preinvasion minesweeping and underwater demolition team operations.

After the 20 October landings, the warship delivered call fire in support of the troops advancing ashore and defended the invasion fleet against the heavy enemy air attacks launched against it.

Soon thereafter, she concluded her part in the Philippine operation and retired to Ulithi Atoll where she joined the screen of the Fast Carrier Task Force.

For the remainder of her participation in the war Welles cruised with either the fast carriers or with their logistics unit as the flattops launched air strikes on Japan's inner defenses and supported from a distance the invasions at Luzon, Iwo Jima, and Okinawa.

Welles was berthed with the Charleston Group, Atlantic Reserve Fleet, until 10 February 1968 at which time her name was struck from the Navy list.