Career
He plays in midfield, usually in the central attacking role. Blackburn Rovers
O'Sullivan was signed up to the Rovers academy in time for the 2009–10 football season, and has progressed each season from the academy, to the Reserves and has been used occasionally as an unused substitute during the 2012–13 Football League Championship season. On 4 May 2013, he made his professional debut for the first team coming on as a second-half substitute in the final game of the season against Birmingham City.
On 9 January 2014, O'Sullivan joined Southport on a one-month loan deal. On 2 February, the loan was extended until the end of the season. He scored his first goal for Southport on 22 February 2014 in a 3–1 away defeat against Forest Green Rovers.
On 27 March 2014, O'Sullivan scored against Forest Green Rovers for the second time and set up the other in a 2–0 victory for Southport. On 19 September 2014 O'Sullivan joined Accrington Stanley on a one-month loan deal. On 20 October 2014 O'Sullivan loan was extended until 20 December 2014.
O'Sullivan scored 4 goals in 13 appearances. On 26th November 2015 O'Sullivan joined Rochdale on loan until 3rd January 2016. O'Sullivan started three matches, getting booked and substituted in the first half of his first match and sent off in the 12th minute of his third and final match for the club.
He has been called up at all age groups to the Republic of Ireland U21s. In 2011 he featured in all the games for Ireland u19 team that reached the semi final of the euro finals.
