[1] Born in Ballina, County Tipperary, O'Brien first played competitive Gaelic games during his schooling at Nenagh CBS.
He arrived on the inter-county scene at the age of fifteen when he first linked up with the Tipperary minor teams as a dual player before later joining the under-21 sides.
At club level O'Brien is a one-time championship medallist in the intermediate grade as a hurler with Ballina.
O'Brien made his debut for the Tipperary hurlers in the 2014 Waterford Crystal Cup final victory against Clare and was a member of the Tipperary hurling panel in 2016 which went on to win the All-Ireland title.
[3] On 22 November 2020, Tipperary won the 2020 Munster Senior Football Championship after a 0-17 to 0-14 win against Cork in the final.