Assigned next to the 7th Fleet, "McDermut" reported 1 October at Manus Island, the staging area for the Leyte operation. On 11 October, the fleet sortied from Seeadler Harbor, entering Leyte Gulf in the early morning hours of the 20th. On that morning "McDermut", screening the transports as they approached the Dulag landing area, warded off enemy planes and rescued downed American pilots. In the afternoon, she was ordered to join with the destroyers and in an antitorpedo-boat screen in Surigao Strait. Later, as reports of Japanese fleet movements were added to the seemingly constant air attacks on shipping in Leyte Gulf, two more ships of Destroyer Squadron 54 (DesRon 54), and , joined the screen.