Tigers coach Brad Brownell said neither player would hire an agent, meaning they could return for a final college season after getting evaluated by pro personnel.
Reed was Clemson's leading scorer this season at 15.8 points a game. Mitchell averaged 12.2 points a game and led the Tigers with 119 assists this season.
Brownell says this was the next step for Reed and Mitchell as they pursue goals of playing in the NBA.
College players who enter the NBA draft have until June 11 to withdraw their names for consideration. The draft is on June 21.
Reed and Mitchell helped Clemson go 25-10 and win a program-record 11 games in Atlantic Coast Conference competition.
More AP college basketball: https://collegebasketball.ap.org; https://twitter.com/AP-Top25 and https://www.podcastone.com/ap-sports-special-events