Ellis began swimming for the Siloam Springs Flyers at the age of 5 then transitioned to his competitive swimming career in Fayetteville at the age of 9 for the Razorback Aquatic Club. Throughout his career in Arkansas he also competed for RAC, North West Arkansas Aquatics, and for a time was trained under a dear friend and mentor, Matt Adams, which eventually lead to swimming for the Aquahawgs. As an Arkansas swimmer he broke multiple state and LSC records in backstroke, butterfly and freestyle, five of the seven high school state records, and was nationally ranked in six different events. While competing for the Aquahawgs he finished in the top three in a multitude of events at the winter and summer USA Junior National Championships and was top eight in multiple winter and summer USA Swimming National Championships. He held the top time in the nation for the 2010 recruiting class in the 200 Meter backstroke and landed a spot on the 2010 Junior World Cup team and USA Swimming Junior National team. After swimming club in Arkansas he went on to compete for the University of Arizona where he helped the team to two fourth place finishes in 2011/2012 and a third place finish in 2013 at the NCAA Championships. He was an NCAA All-American, a Semi-Finalist at the 2012 U.S. Olympic Trials, and won a gold at the 2013 USA Swimming National Championships in the 400 Freestyle Relay.