John O'Leary may refer to:

• John O'Leary (journalist), editor of the Times Higher Education Supplement
• John O'Leary (actor), (1926–2019), American actor in My Chauffeur
• John O'Leary (blues harmonica artist), British blues harmonica player, originally with the band Savoy Brown

• John O'Leary (ambassador) (1947–2005), U.S. ambassador to Chile
• John O'Leary (Fenian) (1830–1907), Irish nationalist who was imprisoned in England
• John O'Leary (Kerry politician) (1933–2015), Irish Fianna Fáil party politician and TD for Kerry South
• John O'Leary (Wexford politician) (1894–1959), Irish Labour party politician and TD for Wexford
• John F. O'Leary (1926–1987), U.S. head of Federal Energy Administration

• John O'Leary (Canadian football) (born 1954), Canadian football running back
• John O'Leary (Gaelic footballer) (born 1961), Irish Gaelic footballer
• John O'Leary (golfer) (1949–2020), Irish golfer
• John O'Leary (sport shooter) (1880–?), British Olympic sport shooter
• Jack O'Leary (c. 1929–1983), American football and basketball coach, college athletics administrator

• John Leary (disambiguation)

This disambiguation page lists articles about people with the same name.
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