Jim Walmsley is an American ultrarunner widely regarded as one of the most talented trail and ultra-distance runners in history. Born in Scottsdale, Arizona, Walmsley attended the United States Air Force Academy, where he captained the cross country team. After graduating, he served as a nuclear missileer at Malmstrom Air Force Base in Montana before discovering ultrarunning and turning professional.\n\nWalmsley rose to prominence with consecutive JFK 50 Mile victories in 2015 and 2016, earning UltraRunner of the Year honors four straight years from 2016 to 2019. He won Western States 100 four times (2018, 2019, 2021, 2024), setting the course record of 14:09:28 in 2019. In 2023, he became the first American man to win UTMB, finishing in a course record 19:37:43.\n\nA versatile runner across distances, Walmsley set a 50-mile world best of 4:50:07 in 2019 and ran a 2:15:05 marathon at the 2020 U.S. Olympic Trials. He competed in the 2024 Olympic marathon in Paris. Known for his aggressive front-running style and self-coached approach, Walmsley has been based in Flagstaff, Arizona, and more recently in the French Alps.