Gleghorne was a member of the England teams that won the bronze medals at the 2014 and 2018 Commonwealth Games and at the 2017 Men's EuroHockey Nations Championship.

At club level, Gleghorne was a member of the Instonians team that won the Irish Senior Cup in both 2002 and 2004.

Two of his aunts, Margaret Gleghorne and Jackie McWilliams, were also Ireland and Great Britain women's internationals.

Two of his aunts, Margaret Gleghorne and Jackie McWilliams, were also Ireland and Great Britain women's internationals.

[8] In addition to field hockey, in his youth Gleghorne played association football, rugby union and cricket.

His teammates included, among others, Eoin Morgan, William Porterfield, Kevin O'Brien, Boyd Rankin and Gary Wilson.

[9][10] In 2002–03 Gleghorne captained the Royal Belfast Academical Institution team that won the Burney Cup and finished as runners-up in the All Ireland Schoolboys Hockey Championship.

[17][18][19] After spending the 2009–10 season playing for HC Den Bosch in the Hoofdklasse,[15][20] he re-joined Loughborough.

[32][33] He subsequently represented Great Britain at the 2016 Summer Olympics[34][35] and when they won the 2017 Sultan Azlan Shah Cup.

[3][17][37] He was also a member of the England team that won the bronze at the 2017 Men's EuroHockey Nations Championship, scoring in the third place play-off against Germany.