 O'Connell played in all grades of hurling during his secondary schooling at Midleton CBS Secondary School before joining the college's senior hurling side.On 27 March 1994, he lined out at left wing-forward when Midleton CBS suffered a 1–09 to 0–04 defeat by the North Monastery in the Harty Cup final.While the 1994 Harty Cup final was supposed to be his last game, O'Connell was one of 11 Midleton CBS players who repeated the Leaving Cert in an effort to claim the title.