Barry, a son of NBA Hall of Famer Rick Barry, told ESPN that he chose the Gators after taking visits to Florida, Northwestern and Miami -- his father's alma mater.
The 6-foot-6 Barry, who redshirted his freshman season and was able to take advantage of the NCAA's graduate transfer rule, averaged 19.7 points this past year for the Cougars.
Barry graduated over the weekend and still has a year of eligibility remaining.
"I really like Coach [Mike] White, his integrity, his honesty with me, and his style of play," Barry said in a statement released by the College of Charleston. "He and I both feel that I can make an immediate contribution on the court and help the team chase the goals of winning an SEC Championship and getting to the NCAA tournament next season."
Barry is a 4.0 student who said he intends to major in nuclear engineering at Florida.