As well as managing winning senior championship teams in Laois with Portlaoise, he also guided St Laurence's in Kildare and Palatine in Carlow to county titles.
Lillis was working as masseur for the Wexford senior football team in 2005 when he received a four-week ban from the Laois GAC following an under-16 football league final between Portlaoise and Stradbally, which also led to Portlaoise senior club treasurer JP Cahillane receiving a six-month suspension for "verbal abuse and physical interference of the referee".
[3][4][5][6] After a defeat to Dublin in the 2016 Leinster Senior Football Championship, Laois went on to beat Armagh in the qualifiers, but fell short against Lillis's native Clare in the next round.
Lillis tendered his resignation as manager of the Laois senior football team shortly afterwards.
[11] Ahead of the 2022 season, Lillis joined Offaly GAA club Shamrocks, assisting manager Brian Kelly (the former Carlow captain).