 On 1 February 2016, Horwood joined National League team Grimsby Town on loan until the end of the season.Horwood made his Grimsby Town debut eight days later on 9 February 2016, starting the whole game, in a 2–1 win over Bromley.Several weeks later, on 23 February 2016, he set up a goal for Pádraig Amond, who went on to score twice, in a 3–1 win over Woking.