He was a forward with the Kilkenny minor, under-21 and senior teams in the 1970s and collected All-Ireland medals at under-age levels.
He served as manager of the Carlow senior inter-county team in the late 1990s while also having spells with the Dunnamaggin, De La Salle and Carrickshock clubs.
All seven brothers – Brendan, Michael, Ger, Kevin, Liam, Seán and Dermot – would play for Ballyhale Shamrocks, while many of them would also represent Kilkenny at various levels on the inter-county scene.
[3] By 1978 the new club had reached the top of the local hurling world and Fennelly was at full-forward as Ballyhale captured their very first senior county title.
Once again Ballyhale Shamrocks reached the All-Ireland final where the star-studded St. Finbarr's club from Cork provided the opposition.
He was back on the team to collect a second Leinster club title following a six-point victory over Kinnitty of Offaly.
Ballybrown stormed into a six-point lead in the middle of the first-half before Liam Fennelly scored a goal in the twenty-fourth minute.
Fennelly first came to prominence on the inter-county scene as a member of the Kilkenny minor hurling team in the early 1970s.
Eligible for the under-21 grade again in 1977, Fennelly collected a second consecutive Leinster title after a seven-point defeat of Wexford.
After a tense hour of hurling Kilkenny emerged victorious by 2–9 to 1–9 and Febbelly collected an All-Ireland under-21 winners' medal.
[6] Shortly after ending his involvement at under-21 level Fennelly joined the Kilkenny senior hurling team.
[7] Fennelly was on and off the Kilkenny team until the early 1980s when a broken leg ended any hope of making the breakthrough at senior level.
In 1996 Fennelly ventured into inter-county management for the very first time when he took charge of the Carlow senior hurling team.
Under Fennelly the club began the climb again, winning the intermediate title in 2000 before getting back to the senior final in 2002.
Fennelly then moved to De La Salle in Waterford and although they didn't win anything, he returned a couple of years later to join the backroom team as they won county and Munster titles before falling to Portumna in the All Ireland decider.