The 22-year-old striker joins Danny Boshell, Jamie Clarke and Matt Heywood in agreeing to have his contract cancelled.
North, who came through the ranks at Blundell Park, made over 80 appearances in just over five-and-a-half years with the League Two club.
A brief statement on Grimsby's official website read: "We would like to wish Danny all the best for the future."
Source: Team Talk
