The USS Leonis (AK-128) was a Crater-class cargo ship that served with the United States Navy during World War II. Originally laid down as the Liberty ship SS Key Pittman on 21 November 1942 by Permanente Metals Corporation in Richmond, California, she was launched on 22 December 1942 under a Maritime Commission contract. As a Liberty ship, she was part of the wartime effort to rapidly produce cargo vessels capable of supporting military operations across the Pacific theater. Initially controlled by the War Shipping Administration, Key Pittman was the first Liberty ship to transit from Milne Bay to Oro Bay with supplies for the New Guinea campaign, arriving at Oro Bay on 11 June 1943. She departed on 16 June and returned to Milne Bay on 17 June, marking the end of Operation Lilliput, which had involved Dutch ships prior to her arrival. The Navy acquired her on 6 October 1943, renamed her USS Leonis on 11 October, and commissioned her on 25 October 1943. Following her shakedown along the West Coast, Leonis set sail from San Pedro on 6 December with cargo destined for Pacific islands. She arrived at Pago Pago in American Samoa on 22 December and remained there until 1 January 1944, before heading to Funafuti Atoll in the Ellice Islands. Throughout early 1944, she shuttled cargo among the Marshall, Gilbert, and Ellice Islands, supporting the Allied island-hopping campaigns. She arrived at Pearl Harbor on 19 April and was assigned to the V Amphibious Corps, transporting troops and supplies to the Mariana Islands, arriving off Saipan on 20 June, just five days after the initial landings. Leonis continued to support Pacific campaigns, including the Palau Islands, where she arrived at Kossal Passage on 20 September 1944. She remained off Peleliu until mid-November, transporting Marines and passengers from various island bases. After returning to San Francisco on 18 December 1944, she was reloaded and sailed again on 11 January 1945, serving as a fleet issue ship in the Philippines, mainly supplying the fleet with dry stores and medical provisions throughout the remainder of the war. Following Japan's surrender, Leonis departed Leyte Gulf on 4 September 1945 and arrived in California a month later. She was decommissioned at Norfolk, Virginia, on 5 December 1945, and returned to the War Shipping Administration, reverting to her original name, Key Pittman. She was laid up in the National Defense Reserve Fleet and eventually sold for scrapping in 1967, with her scrapping completed in 1968. During her service, USS Leonis earned two battle stars for her participation in World War II operations, marking her as a notable vessel in the Pacific theater.

This description has been generated using GPT-4.1-NANO based on the Vessel's wikidata information and then modified by ShipIndex.org staff.