Flanagan joined the Feohanagh-Castlemahon club at a young age and played in all grades at juvenile and underage levels before eventually joining the club's top adult team.
Limerick
Minor and under-21
Flanagan first played for Limerick at minor level. On 22 July 2014, he was at left wing-forward when Limerick won their second successive Munster Championship title after a 0-24 to 0-18 defeat of Waterford in the final. Flanagan was moved to left corner-forward for the subsequent All-Ireland final against Kilkenny on 7 September 2014. He scored two points from play in the 2-17 to 0-19 defeat. Flanagan's second and final season with the Limerick minor hurling team ended with an All-Ireland quarter-final defeat by Galway. Flanagan subsequently joined the Limerick under-21 hurling team in 2016 and played as a left corner-back during the team's unsuccessful championship campaign. After being dropped from the starting fifteen the following year, Flanagan won a Munster Championship medal as a non-playing substitute after a 0-16 to 1-11 defeat of Cork in the final. On 9 September2017, Flanagan was an unused substitute in Limerick's 0-17 to 0-11 defeat of Kilkenny in the All-Ireland final.
Senior
Flanagan made his senior start during the 2018 season in a pre-season Munster Leaguegame. He scored 1-02 from play in the 2-23 to 1-21 defeat of Cork. Flanagan later collected his first silverware at senior level when Limerick defeated Clare by 0-16 to 0-10 to win the Munster League. He made his National League debut on 28 January 2018 in a 1-25 to 0-18 defeat of Laois, before later making his first championship start in a defeat of Tipperary. On 19 August 2018, Flanagan was at full-forward and scored one point when Limerick won their first All-Ireland title in 45 years after a 3-16 to 2-18 defeat of Galway in the final. He ended the season by being nominated for an All-Star Award. On 31 March 2019, Flanagan started Limerick's National League final meeting with Waterford on the bench. He was introduced as a 55th-minute substitute for Graeme Mulcahy and collected a winners' medal following the 1-24 to 0-19 victory. On 30 June2019, Flanagan won a Munster Championship medal after coming on as a 66th-minute substitute for Peter Casey in Limerick's 2-26 to 2-14 defeat of Tipperary in the final.
