Orestes was laid down as landing ship tank USS LST–135 at Chicago Bridge and Iron Company, Seneca, Illinois, on 8 July 1943, and launched on 16 November 1943, sponsored by Mrs. Bernard Sharp.

She began motor torpedo boat tending operations at Aitape on 23 August 1944, transferred to Mios Woendi a month later, and on 12 November 1944 joined General Douglas MacArthur’s Philippines invasion forces at Leyte.

On 30 December 1944, an Aichi D3A "Val" dive bomber came in low on the starboard side and crashed into Orestes amidships, causing heavy damage and killing 45 members of her crew.

Lieutenant Dent was awarded the Navy and Marine Corps Medal for heroism in the saving of the lives of American Naval personnel in action.

Orestes served under the Commander Motor Torpedo Boats, Philippine Sea Frontier, until 17 December 1945, when she sailed eastward with naval passengers for Pearl Harbor, Hawaii, and the United States, arriving at San Pedro, California, on 3 February 1946.