Michael O'Neill

Michael O'Neill may refer to:
 * Michael O'Neill (diplomat) (born 1967), British diplomat
 * Michael O'Neill (academic) (1953–2018), English poet and academic
 * Michael O'Neill (actor) (born 1951), American actor
 * Michael O'Neill (educator), pioneer in non-profit management education
 * Michael O'Neill (footballer) (born 1969), Northern Irish football player and manager
 * Michael O'Neill (politician) (1909–1976), Irish politician
 * Michael E. O'Neill (born 1946), chairman of Citigroup
 * Mike O'Neill (basketball) (born 1928), American basketball player
 * Mike O'Neill (baseball) (1877–1959), Irish-born American starting pitcher and left fielder in Major League Baseball
 * Mike O'Neill (ice hockey) (born 1967), Canadian professional ice hockey goaltender
 * Mike O'Neill (lacrosse), three-time All-American lacrosse player
 * Mike O'Neill (musician) (born 1970), Canadian singer-songwriter
 * Mike O'Neill (rugby league) (born 1960), English rugby league footballer of the 1970s, 1980s and 1990s
 * Mike O'Neill, winner of a 2006 Costume Designers Guild Award
 * Michael O'Neill, founder of the Informed Medical Options Party, a minor political party in Australia
 * Mikey O'Neill (footballer) (born 2004), English footballer