|Assumed office |
|Born||28 December 1971|
|Political party||Sinn Féin|
|Spouse(s)||Gillian O'Brien (m. 2008)|
|Alma mater||Cork Institute of Technology|
He was a member of Cork City Council from 2000 to 2011. O'Brien also has a sporting background. He is a former board member and chairman of Cork City Football Club, having been a founding member of the supporters' trust, FORAS. He is also a member of St. Vincent's GAA Club.
O'Brien was criticised by the Minister of Education Ruairi Quinn over his position on the Household Charge. O'Brien responded by saying he had been elected to implement just and fair laws, and described the household tax as being neither.
He is the Sinn Féin Junior Spokesperson for Finance, and Public Expenditure and Reform.
| Sinn Féin Teachta Dála for Cork North-Central