Born in, County, Lennon first excelled at hurling in his youth. He enjoyed All-Ireland successes at colleges level with Saint Lennon made his debut on the inter-county scene at the age of seventeen when he first linked up with the minor team
Lennon made his senior debut during the 2015 league.
Saint Kieran"s College All-Ireland Colleges Senior Hurling Championship (2): 2010, 2011 (sub) Leinster Colleges Senior Hurling Championship (2): 2010, 2011 (sub) Bennettsbridge All-Ireland Junior Club Hurling Championship (1): 2015 (c) Leinster Junior Club Hurling Championship (1): 2014 (c) Kilkenny Junior Hurling Championship (1): 2014 (c) Kilkenny Leinster Senior Hurling Championship (1): 2015 (sub) Leinster Under-21 Hurling Championship (1): 2012 (sub) All-Ireland Minor Hurling Championship (1): 2010 (sub) Leinster Minor Hurling Championship (1): 2010 (sub).
