In May 1925 Johnny Mullan (Seán Ó Maoláin), the local school teacher, called a meeting with the aim of establishing a new Gaelic football club in Glenullin.
[1] The club decided to name itself after Irish rebel John Mitchel and wore green and white hooped jerseys.
Glenullins original football pitch was Tinkers Park in Coolcoscreghan townland, on the junction of the Lisnascreghog and Glen roads.
1951 was the year John Mitchel's first wore the green and gold hoops, which they currently wear today.
They won their first Derry Senior Championship in 58 years by defeating Ballinderry in the final at Dean McGlinchey Park, Ballinascreen.
They were managed that year by Liam Bradley, and joint captain with Brian Mullan was his son Paddy.
In 2010, Glenullin player Eoin Bradley brought shame upon the club, assaulting referee Declan O'Connor by punching him in the face.
When they discovered that Declan O'Connor was scheduled to referee, they refused to field a team which ended up costing them 3 league points.