[citation needed] O'Brien joined the Newport club at a young age and played in all grades at juvenile and underage levels.
On 23 October 2016, O'Brien captained Newport in the Tipperary Intermediate Championship final against Thurles Sarsfields.
He won a Munster Championship medal as a non-playing substitute on 28 July 2010 following Tipperary's 1-22 to 0-17 defeat of Cork in the final.
[4] On 1 June 2011, O'Brien made his first appearance for the Tipperary under-21 team when he came on as a substitute for James Barry at centre-back in a 4-12 to 1-16 defeat of Waterford.
On 9 June 2013, O'Brien made his first appearance for the intermediate team when he lined out at right corner-back in a 0-20 to 0-15 defeat of Cork.
[9] O'Brien made his first appearance for the team on 22 July when he came on as a 45th-minute substitute for James Barry in a 0-28 to 3-16 defeat of Clare in the All-Ireland quarter-final.