Gary John Castledine (born 27 March 1970) is a Scottish former professional footballer born in Dumfries who made 66 appearances in the Football League playing as a midfielder for Mansfield Town.
Prior to his stint with Mansfield, Castledine played at Shirebrook Town F.C. from August 1990 to February 1991. In July 2012, he was appointed manager to Shirebrook.