Gboly Ariyibi has completed his transfer to Nottingham Forest, joining the Championship club for an undisclosed fee.
The 22-year-old winger scored four goals in 93 appearances for Chesterfield after signing as a free agent in August 2014.
Chris Turner, Chesterfield’s director of football, commented: “It’s a great move for Gboly, both personally and professionally and we wish him all the very best.
“The decision that we took last August to reject offers for Gboly affected him for a long period and illustrated what can happen to a player when they are denied the opportunity to progress in their career.
“He’s got the ability to go much higher in the game and if he does make the progress we know he’s capable of, we will benefit as a club.”