Grimsby's highest attendance in the 2015–16 season was in the 2–0 victory over local rivals Lincoln City, a gate of 7,650 which also was the highest attendance of all the clubs in the 2015–16 season. Grimsby would play in the final of the FA Trophy, but they lost, the final result was 1–0 to Halifax Town. The week before, Grimsby Town beat Forest Green Rovers 3–1 in the 2016 National League play-off Final at Wembley, seeing Grimsby promoted back to League Two after a six-year absence from the Football League.