Simms had until June 3 to pull out of the draft. He had announced in March his intentions to go pro. He did not hire an agent, making him eligible to return for his senior year.
Simms is a 6-foot-8 forward from Palmyra, Virginia, who was a third-team All-Atlantic Coast Conference pick this past season after averaging a team-best 13 points a game. He also averaged 7.2 rebounds and 2.6 assists.
He was instrumental as Clemson defeated three programs ranked in the top six for the first time in school history in No. 3 Duke, No. 5 Louisville and No. 6 Florida State.
Simms had 20 points, 8 rebounds and 6 assists as the Tigers won for the first time at North Carolina, beating the Tar Heels 79-76 in overtime last January.
Simms' return means Clemson will bring back four of five starters from last season.