Lennon played hurling as a schoolboy with the Kilkenny CBS team, while simultaneously lining out at juvenile and underage levels with the Éire Óg club.
He progressed onto the club's senior team and won three Kilkenny SHC titles between 1944 and 1947.
He was a non-playing substitute, alongside his brother-in-law Jim Langton, in the defeat of Cork in the 1947 All-Ireland final.
[3][4] Lennon spent much of his later years working as a coach and selector at all levels with the Clara club.
Lennon died on 8 September 1990 after taking ill at a Clara juvenile hurling game at Mosney Holiday Camp.