James Gunnar Nixon (born January 13, 1993) is an American track and field athlete who competes in the decathlon. He broke the American high school record for the event in 2011 and was the World Junior Champion in 2012. He won his first national title indoors in 2013 and was runner-up at the 2013 USA Outdoor Track and Field Championships. His personal record for the decathlon is 8313 points at the 2013 IAAF World Championships.