At club level he played with Garnish and Beara and was also a member of the Cork senior football team.
O'Sullivan began his Gaelic football career at juvenile and underage levels with Garnish, before winning several Beara Junior Championship titles with the club's top adult team.
[2] O'Sullivan first appeared on the inter-county scene during a two-year stint with the Cork minor team before later lining out with the under-21 side.
[3] O'Sullivan served as a selector with the Cork minor football team during Bobbie O'Dwyer's tenure as manager.
In 2019, he was part of the management team that secured the All-Ireland Minor Football Championship title after a win over Galway[4]