[citation needed] Cahill joined the Ballingarry club at a young age and played in all grades at juvenile and underage levels.
As a member of the Ballingarry senior hurling team, Cahill won South Tipperary Championship medals in 1996, 1998 and 2001.
Cahill made his senior debut for Tipperary on 18 February 1996, replacing Aidan Ryan in a National Hurling League defeat of Cork at Páirc Uí Rinn.
On 14 September 1997, Cahill came on as a substitute for Michael Cleary in Tipperary's 0-20 to 2-13 All-Ireland final defeat by Clare at Croke Park.
[3] On 16 May 1999, Cahill collected his first silverware at senior level when he won a National Hurling League medal after a 1-14 to 1-10 defeat of Galway in the final.
[5] On 9 September 2001, Cahill was a non-playing substitute when Tipperary won the All-Ireland title for the first time in a decade after a 2-18 to 2-15 defeat of Galway in the final.
[6] After being a regular player for Tipperary during the 2003 National League, Cahill subsequently fell out of favour with the management after a poor performance against Clare in the Munster Championship.
[18] Cahill's four-year tenure as Tipperary minor hurling manager ended with a three-point defeat by Cork in 2017.
[24] Both sides met again in the All-Ireland final on 24 August 2019, with Tipperary recording a 5-17 to 1-18 victory and a third successive championship defeat of Cork.
[32] On 18 July 2022, Cahill was named as the new manager of the Tipperary county hurling team on a three year term, replacing Colm Bonnar.
[36][37][38] In the 2024 Munster Senior Hurling Championship, Tipperary lost by eighteen points to Limerick in round 1 before drawing with Waterford a week later in Walsh Park.