Gillespie, who progressed through the youth system at Brunton Park, has the option of another season.
Manager Keith Curle told the club’s official website: “We all know what Mark is capable of and we’re delighted that he’s staying with us.
“He’s been unlucky with injuries and, if we can keep him clear of that, we’re sure he’ll continue with the progression we’ve already seen.
“He has a very professional approach and I’m sure he’ll come back for pre-season ready to kick on and stake a claim.”
Gillespie made his first-team debut as a late substitute at Norwich in May 2010 and has made a total of 78 appearances for the Cumbrians, 21 of which were last season.