John Fleck becomes the second player of the day to agree a contract extension with the Spireites.
The Scotland international joined Chesterfield in September 2024 after leaving Blackburn Rovers.
Fleck made 20 appearances in all competitions last term as Paul Cook’s side made the League Two play-offs.
After putting pen to paper, he said: “I’m delighted to get the deal over the line; it was pretty straightforward enough to get done.
“I’ve seen we’ve signed a couple of good players and managed to get Dilan Markanday back as well, which is fantastic for the club.
“It was a disappointing end to last season and hopefully we can do one better this time around.”
