Background
O'Halloran grew up in Clifden. He is the son of Aidan O'Halloran, who was on the All-Ireland winning with Offaly football team in 1982.
O'Halloran grew up in Clifden. He is the son of Aidan O'Halloran, who was on the All-Ireland winning with Offaly football team in 1982.
He attended Garbally College in Ballinasloe, playing for the side in the Connacht Junior Cup, scoring a try as they beat Coláiste Iognáid in the final.
He primarily plays as a fullback or on the wing. O'Halloran currently plays for Irish provincial side Connacht in the Pro12. O'Halloran played rugby with Connemara at a young age.
O'Halloran later transferred to Cistercian College in Roscrea and played for them in the Leinster Senior Cup. In addition to rugby, O'Halloran played Gaelic football growing up. He played with Clifden at club level and was on the Galway minor panel for two years.
Connacht
O'Halloran was involved with the Connacht youth set up from a young age, and trained with the academy squad at just 16 years old. He made his debut against Olympus Madrid in the 2009–10 Challenge Cup, scoring a try 30 minutes into the game. O'Halloran made his league debut in the same season, starting against Scarlets in a 2009–10 Celtic League match on 25 April 2010.
The following season, while still in the academy, O'Halloran made three replacement appearances in the 2010–11 Celtic League, but didn't feature in the Challenge Cup. After graduating from the Connacht academy, O'Halloran was signed on a development contract for the 2011–12 season. On 11 November 2011, O'Halloran scored Connacht's first ever try in the competition against Harlequins in the opening round.
He also featured for Connacht in the 36–10 defeat to Toulouse in and the 23–19 loss against Gloucester, scoring another try against Gloucester. In the 2011–12 Pro12 O'Halloran scored tries in both games against the Cardiff Blues along with tries Leinster Rugby and Glasgow Warriors. In Round 20 of matches, O'Halloran scored a try in a 26–21 victory over Ulster Rugby to take his tally of tries to five in the Pro12 and seven in all competitions.
International
O'Halloran has represented Ireland internationally at under-age level. He played for both Ireland schools and the Ireland under-20s. During the 2011–12 season, he was called up by Declan Kidney to train with the senior team.