After returning home from Burnley, Reilly decided to return to Gaelic football with his local club Killygarry.
Killygarry reached their first county final in 51 years in 2022,[5] facing Gowna on 16 October. Reilly scored a lobbed goal in the first half, but Gowna ran out seven-point winners.[6]
University
On 28 February 2009, Reilly was at wing forward as DIT faced Cork IT in the Sigerson Cup final. Reilly scored one point as DIT suffered a five-point loss.[7]
On 23 February 2013, Reilly played in his second Sigerson final, with DIT facing UCC in the decider. DIT claimed their first Sigerson title after a dominant display.[8]
Inter-county
On 7 July 2007, Reilly made his senior championship debut for Cavan in a qualifier loss to Mayo.[9]
On 4 August 2013, Reilly started in his first All-Ireland quarter-final against Kerry. Reilly scored a point from a 45 as Cavan lost by six points.[10]
On 26 April 2014, Cavan faced Roscommon in the National League Division 3 final, and Reilly scored 3 points in the narrow defeat.[11]
On 3 April 2016, Reilly was at wing forward against Galway in the National League as Cavan earned promotion to the top flight for the first time in 15 years.[12] On 24 April, Reilly scored a point in the Division 2 Final against Tyrone, with Cavan losing by five points.[13]
Cavan met Roscommon once again in the National League Division 2 Final on 1 April 2018. Reilly scored a goal from a first half penalty as Cavan suffered a 4–16 to 4–12 loss.[14]
In 2019, Reilly lined out at wing back in his first Ulster Final, with Cavan facing Donegal on 23 June. Two late goals couldn't stop Cavan from falling to a five-point defeat.[15]
On 22 November 2020, Reilly played in his second Ulster Final as Cavan met Donegal for the second year in a row. Reilly scored a point as Cavan claimed their first Ulster title since 1997.[16] On 5 December, Reilly scored 3 points as Cavan exited the championship to Dublin at the semi-final stage.[17] Reilly received his first All-Star nomination at the end of the season.[18]
On 9 July 2022, Reilly started on the bench as Cavan took on Westmeath in the inaugural Tailteann Cup decider at Croke Park. Reilly was introduced as a late substitute in the four-point loss.[19]