The striker will play at the Proact next season after being released by Doncaster Rovers.
He was sold on what John Sheridan had to say about the club as the Spireites look to put together a push for promotion.
Mandeville told the club’s website: “We had a good chat and I liked what I heard. It's an excellent set-up and I’m looking forward to it.”
Assistant-manager Glynn Snodin added: “Liam could have stayed in the Football League, so credit to him for dropping down to the National League to join us.
“He creates and scores goals and we think we can get the best out of him.”