The striker, 32, leaves the Spireites after four years at the club following the expiration of his contract.
Announcing his departure on social media, he said: “So after a great four years at Chesterfield Football Club my time has come to move on!
"I would like to thank every team mate I have played with and every single Spireites supporter for the fantastic support home and away!
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"I will be back to watch a few games and hope you get that promotion you all deserve.”
Denton joined Chesterfield from Alfreton Town in August 2018 when Martin Allen was manager.
The towering forward, known for his aerial presence in both boxes, scored some important goals for the club when he first signed and started the 2020/2021 campaign on fire, bagging nine goals in 15 games, before he suffered a serious knee injury which ended his campaign.
He made a return last summer before suffering another knee injury which ruled him out for the majority of last season.
His last goal came in the 3-2 defeat to Bromley in April.
Manager Paul Cook spoke highly of ‘Dents’ and he was set to be offered a new contract but he is now a free agent.