St. Colman's College O'Leary first came to prominence as a hurler with
St. Colman's College in
Fermoy. On 18 February 2017, he scored 1-01 from play for St. Colman's in a 2-22 to 1-06 defeat by
Our Lady's Secondary School from
Templemore in the
Harty Cup final.
University College Cork On 23 February 2019, O'Leary lined out at right corner-back for
University College Cork when they faced
Mary Immaculate College in the
Fitzgibbon Cup final. He scored a point from play in the 2-21 to 0-13 victory. O'Leary played in a second successive
Fitzgibbon Cup final on 12 February 2020. Selected at left wing-back but mostly playing in a sweeper role, he ended the game with a second successive winners' medal after the 0-18 to 2-11 defeat of the
Institute of Technology, Carlow.
Castlelyons O'Leary joined the
Castlelyons club at a young age and played in all grades at juvenile and underage levels. On 8 October 2016, he scored 1-1 from midfield in a 2-13 to 1-15 Cork Minor Championship final replay defeat by
Ballygiblin.
Imokilly In 2017, O'Leary was added to the
Imokilly senior team. On 22 October, he was at centre-back when Imokilly defeated
Blackrock by 3-13 to 0-18 to win the
Cork Senior Championship. On 14 October 2018, O'Leary won a second successive Cork Senior Championship medal from centre-back, following Imokilly's 4-19 to 1-18 defeat of
Midleton in the final.
Cork Minor and under-21 O'Leary first played for Cork at minor level on 8 April 2015 in a 2-20 to 1-13
Munster Championship defeat of
Limerick. An anomaly in the championship format saw Cork face the same opposition in the semi-final, with Limerick reversing the result. O'Leary was eligible for the minor grade again in 2016 and was appointed captain of the team. He played his last game in the minor grade on 30 June 2016 in a 0-23 to 1-12 defeat by
Tipperary in the
Munster semi-final. On 20 June 2018, O'Leary made his first appearance for the Cork under-21 hurling team in a 0-23 to 1-17 defeat of
Waterford. He later won a
Munster Championship medal on 4 July following Cork's 2-23 to 1-13 defeat of Tipperary in the final. On 26 August, O'Leray was at left corner-back in Cork's 3-13 to 1-16
All-Ireland final defeat by Tipperary, in what was his last game in the grade.
Senior On 2 January 2019, O'Leary made his first appearance for the Cork senior hurling team in a 1-24 to 1-18 pre-season
Munster League defeat by Waterford. He was later included on the Cork panel for the
National League but made no appearances throughout the six-game campaign. O'Leary made his first competitive appearance on 12 May when he lined out at left corner-back in a 2-28 to 1-24 defeat by Tipperary in the
Munster Championship. ==Career statistics==