(13366) 1998 US24, provisional designation 1998 US24, is a Jupiter trojan from the Greek camp, approximately 33 kilometers (21 miles) in diameter. It was discovered on 18 October 1998, by astronomers with the Lowell Observatory Near-Earth-Object Search at the Anderson Mesa Station near Flagstaff, Arizona, in the United States. The dark Jovian asteroid is a slow rotator with a long rotation period of potentially 400 hours. It has not been named since its numbering in January 2000.