The defender, who has regularly featured in the Spireites pre-season games, is delighted to have signed for the club. He said, "Chesterfield is a club that's going places, it didn't need to be sold to me and it's a great step in my career.
"I'm delighted to have signed for Chesterfield and I can't wait to get going," added Brown.
Speaking about the signing, Chesterfield's Chief Executive, Chris Turner, said: "Matty Brown is a player that Paul Cook has been looking at over the summer and during the pre-season games. The manager and myself feel that Matty has a lot to offer on the pitch and will be a great addition to the football club."
Turner added: "I would also like to thank Marine for their support during Matty's move to Chesterfield, they have been outstanding throughout."