Spearmon is a graduate of Fayetteville High School and attended the University of Arkansas, where he competed collegiately for two seasons before turning pro. While at Arkansas, he won the 200 meters NCAA Outdoor title in 2004 and 2005 as well as the NCAA Indoor 200 m title in 2005. In August 2005, he won the silver medal in the 200 m at the 2005 World Championships and in August 2007, he won the bronze medal at the 2007 World Championships. Spearmon won the 200 m at the USA outdoor athletics championships in 2006 and finished second in 2007. At the 2009 World Championships in Berlin he won another bronze. He ran a world best time of 31.88 for the 300 m indoors in February 2006.