Between 29 September and 6 October, "Witter" made a roundabout voyage from Milne Bay via Treasuries and back to New Guinea at Humboldt Bay. At Humboldt Bay, she reported for duty to TU 77.7.1 for the Leyte operation. Her task unit, a part of the 7th Fleet Service Force, departed Humboldt Bay on 12 October to take up replenishment station at sea some 180 miles west of the already-invested Palau Islands. At mid-month, the oilers she escorted refueled the Leyte invasion force at sea and, on the 18th, headed for the anchorage at Kossol Passage in the Palaus. After two days in the Palaus, "Witter" and her charges got underway to join the main force in Leyte Gulf. They arrived in the gulf three days after the 20 October assault.