John O'Sullivan
John O'Sullivan may refer to:
Sports
- John O'Sullivan (cricketer), New Zealand cricketer
- John O'Sullivan (cyclist), Australian cyclist
- John O'Sullivan (footballer, born 1993), Irish footballer for Shelbourne
- John O'Sullivan (footballer, born 2006), Irish footballer for Shamrock Rovers
- John O'Sullivan (rugby league), New Zealand rugby league footballer
- John O'Sullivan (rugby union), Irish rugby union footballer
- John Lack O'Sullivan, Gaelic footballer and Australian rules footballer
Politics and government
- John O'Sullivan (Cork politician), Irish Fine Gael Party politician, Senator, later TD for Cork South-West
- John O'Sullivan (Illinois politician), member of the Illinois House of Representatives
- John C. O'Sullivan, politician in Ontario, Canada
- John M. O'Sullivan, Irish Cumann na nGaedhael/Fine Gael politician, TD, cabinet minister and academic
Other
- John O'Sullivan (columnist), British conservative columnist and editor
- John O'Sullivan (engineer), Australian astronomer and electrical engineer, and one of the inventors of Wi-Fi
- Sir John O'Sullivan (soldier), Irish soldier, Quartermaster general to Prince Charles Edward Stewart during the Jacobite Rising of 1745
- John Francis O'Sullivan, Irish-American awarded the Medal of Honor during the Indian Wars
- John L. O'Sullivan, journalist who popularized the phrase "Manifest Destiny"