Richmond is currently working out in Chicago and has various options for an agent, according to the release.
"I enjoyed my time at the University of Illinois and would like to thank the coaching staff and my teammates for everything they've done for me," Richmond said in a statement. "At this time, I'm ready to follow my dreams and achieve my life-long goal of playing in the NBA."
Richmond had an up-and-down freshman season for the Illini. He missed the team's two NCAA tournament games due to an athletic code violation and also sat out a previous game after returning home due to a personal matter.
On the court, he showed flashes of what made him a McDonald's All-American, but he also struggled at times. He averaged 7.6 points and 5.0 rebounds in 31 games.
"Jereme is an extremely talented player who helped us at nearly every position," Illinois coach Bruce Weber said in a statement. "His versatility and ability to impact the game in a number of different areas are skills that will help him greatly as he pursues his dream of playing professional basketball. We wish Jereme the best and thank him for all he has meant to the Illinois basketball program, from the time he committed as a high school freshman through his contributions this past season."
Weber said last week Richmond had been attending team workouts and was expected to return next season.
ESPN NBA draft analyst Chad Ford has Richmond ranked as the No. 45th best prospect in 2011 and has him going anywhere from the late first round to early second round.
Richmond committed to Illinois as a high school freshman and was considered one of the program's biggest recruits. He was the ESPNChicago.com Player of the Year and a McDonald's All-American as a high school senior at Waukegan.
Illinois Fire coach Mike Irvin, Richmond's former club coach, talked to Richmond before he decided to enter the draft.
"Hopefully, this decision works out for Jereme," Irvin said. "He's definitely talented. I think he has what it takes to make it in the NBA."
The news did not affect how De La Salle senior forward and Illinois recruit Mike Shaw felt about next season's Illini team.
"I wish him the best of luck," Shaw said. "I knew there was a chance he'd go to the NBA. We still have a great coaching staff, great players coming in and great players already there. Everybody's going to have to step [up] and accept their role and work hard every day."
Scott Powers covers high school and college sports for ESPNChicago.com and can be reached at email@example.com.