John O'Leary may refer to:
Arts and entertainment 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), (1944–2024) British blues harmonica player, originally with the band Savoy Brown
Government and politics 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
Sports John O'Leary (Canadian football) (1954–2026), 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) (1880–1967), British Olympic sport shooter Jack O'Leary (1929–1983), American football and basketball coach, college athletics administrator Jack O'Leary (runner) (born 1997), Irish long-distance runner
Other John O'Leary (motivational speaker), American motivational speaker and author
See also John Leary (disambiguation)