Freeman, 20, who came through the club's youth system, had expressed his desire to leave the City Ground.
And Forest boss Sean O'Driscoll told the Nottingham Post: "Kieron has made it perfectly clear that he does not want to be at the club, which is his prerogative to be honest.
"From the moment we walked through the door, it was clear he did not want to be at the club. It is probably best for all parties that we part company."
Freeman spent the second half of last season across the River Trent on loan at Notts County.