Chesterfield have beaten off competition from several clubs to sign Ian Evatt.
The versatile 21-year-old made 20 appearances for Derby last season, but was one of a number of players released by the Rams this summer.
Evatt, a product of Derby's youth system, is primarily a midfielder but has also played in defence and up front.
Chesterfield boss Roy McFarland said: "When I realised Ian was being released he was my number one target to bring to the club.
"He can play in several positions but I see him playing in a central midfield role for Chesterfield.
"There was a lot of interest from other clubs, so I am delighted that Ian has chosen to join the Spireites."
Evatt revealed that McFarland was a major factor in his decision to move to Saltergate.
"I have joined Chesterfield because of Roy McFarland's big reputation and positive attitude," said Evatt.
"Chesterfield has a young side which wants to play football and I think we have a really good chance this season."