The club have agreed to terminate the contract and registration of Mitch Rose with immediate effect, with the player moving to join Notts County.
Speaking of his departure, Town boss, Michael Jolley told gtfc.co.uk: “We thank Mitch for his huge contribution to Grimsby Town over the last 18 months.
“He was a vital player in our efforts to remain in League Two last season. He has consistently stepped forward and taken responsibility at key times.
“We wish him nothing but the best for the future and thank him for his work at Grimsby Town.”