O'Riordan's father, Michael, and his brothers, Kevin and Alan, have also played at various levels with Tipperary.[2]
Gaelic Football
O'Riordan made his senior debut during the 2014 league. O'Riordan immediately became a regular member of the starting fifteen and has won one National League (Division 4) medal.[3]
In January 2021, O'Riordan was nominated for an All-Star award.[11][12]
AFL
In October 2015, O'Riordan signed a rookie contract with the Sydney Swans in the AFL.[13]
In 2018, O'Riordan trained under 2005 premiership Swan Tadhg Kennelly.[14] On 15 July 2018, O'Riordan became the third Irish player to play for Sydney, making his debut in round 17 against North Melbourne.[14]
In August 2022, O'Riordan announced his retirement from the AFL due to a chronic hip injury. He played 34 games since joining the Sydney Swans in October 2015.[15][16]
^The 2020 season was played with 17 home-and-away matches per team (down from 22) and 16-minute quarters with time on (down from 20-minute quarters with time on) due to the impact of the COVID-19 pandemic.