Scott Gordon Jurek is an American ultramarathoner, author, and public speaker. Throughout his running career, Jurek was one of the most dominant ultramarathon runners in the world, winning the Hardrock Hundred (2007), the Badwater Ultramarathon, the Spartathlon, and the Western States 100 Mile Endurance Run (1999–2005). In 2010, at the 24-Hour World Championships in Brive-la-Gaillarde, France, Jurek won a silver medal behind Shingo Inoue and set a new US record for distance run in 24 hours with 165.7 miles. In 2015, Jurek set the Fastest Known Time running record for the 2,189-mile Appalachian Trail.

An ultramarathon, also called ultra distance or ultra running, is a footrace longer than the traditional marathon length of 42.195 kilometres. Various distances, surfaces, and formats are raced competitively, from the shortest common ultramarathon of 31 miles (50 km) and up to 3100 miles. World Championships are held by the International Association of Ultrarunners (IAU) for 50 km, 100 km, 24 hours, and ultra trail running. The Global Organization of Multi-Day Ultramarathoners (GOMU) holds World Championships for 48 hours and 6 days. World Records are ratified and recognized by World Athletics, the IAU, and by GOMU.