Born in
Edmonton, London, O'Cearuill started his career at
Leyton Orient, playing 27
youth team games in the
2004–05 season, before being released in August 2005. He joined
Watford as a youth player for the
2005–06 season, but was released in the summer of 2006. He made his competitive debut for St Patrick's on 7 March 2008, in a
League of Ireland match against
Sligo Rovers. O'Cearuill made a total of 3
UEFA Cup appearances with St. Pats. He left the club in January 2009. He signed for
Harlow Town on 17 September 2009, before signing for
Boreham Wood on 27 October. He signed for
Conference National team
Forest Green Rovers on 6 November. In August 2012 he signed for
Haringey Borough, before joining
Isthmian League Premier Division side
Enfield Town in January 2013.{{cite news ==International career==