O'Malley (Irish: Ó Máille [oː ˈmˠaːl̠ʲə]) is an Irish surname. According to historian C. Thomas Cairney, the O'Malleys were the chiefly family of the Partraige who were a tribe of the Erainn, the second wave of Celts to settle in Ireland between about 500 and 100 BC.[1]
- Maille mac Conall of Umhaill
- Mary Ní Mháille (died 1525)
- Brian O'Malley (director), Irish film and television director
- Bryan Lee O'Malley (born 1979), comic book creator
- Charles O'Malley (disambiguation)
- Conner O'Malley (born 1986), American comedian
- Daragh O'Malley (born 1954), Irish actor
- Desmond O'Malley (1939–2021), Irish politician
- Donogh O'Malley (1921–1968), Irish Fianna Fáil politician
- Edward O'Malley (disambiguation)
- Edwin Joseph O'Malley (1881–1955), Commissioner of Public Markets for New York City
- Ernie O'Malley (1897–1957), Irish Republican Army officer
- Fiona O'Malley (born 1968), Irish Progressive Democrat politician
- Grace O'Malley (c. 1530 – c. 1603), Irish noblewoman and chieftainess
- Henry O'Malley (1876–1936), American fish culturist, United States Commissioner of Fisheries (1922–1933)
- Iseult O'Malley (born 1964), judge of the Supreme Court of Ireland
- Jack O'Malley (Michigan politician), American politician
- Joan O'Malley, Canadian civil servant
- Joe O'Malley (1932–2015), American football player
- John O'Malley (1878–1940), American politician
- John F. O'Malley (1885–c. 1950), American architect
- John J. O'Malley (1915–1970), American architect
- John na Seoltadh Ó Máille (fl. 1568), Gaelic-Irish lord
- J. Pat O'Malley (1904–1985), English singer and actor
- Kate O'Malley (disambiguation)
- Kate O'Malley, a British actress active in the 1990s who was a regular on the last two seasons of Soldier Soldier
- Kathleen M. O'Malley (born 1956), United States federal judge
- Katie O'Malley (born 1962), Maryland state court judge, and first lady of Maryland
- King O'Malley (1858–1953), Australian politician
- Mart O'Malley (1890–1972), Indiana state judge
- Martin O'Malley (born 1963), American politician
- Martin O'Malley (journalist) (born 1939), Canadian journalist
- Mary O'Malley (disambiguation), various including
- Matthew Vincent O'Malley (1878–1931), American politician
- Mick O'Malley (born 1972), Australian boxer of the 1990s and 2000s
- Mike O'Malley (born 1969), American actor
- Nick O'Malley (born 1985), indie-rock musician
- Sir Owen O'Malley (1887–1974), British diplomat
- Pamela O'Malley (1929–2006), Irish-Spanish bohemian, educationalist and radical
- Patrick O'Malley (disambiguation) or Pat O'Malley, various including
- Peter O'Malley (disambiguation)
- Robert Emmett O'Malley (born 1943), Medal of Honor recipient
- Rory O'Malley (born 1980), Broadway actor
- Ryan O'Malley (born 1980), American baseball player
- Ryan O'Malley (American football) (born 1993), American football player
- Séamus O'Malley (1903–2002), Irish Gaelic football player
- Seán Patrick O'Malley (born 1944), Roman Catholic Cardinal
- Sean O'Malley (fighter) (born 1994), American mixed martial artist
- Stephen O'Malley (born 1974), American musician/guitarist, producer, composer, and visual artist
- Susan O'Malley, American sports executive
- Susan O'Malley (artist) (1976–2015), public art, author and museum curator
- T. J. O'Malley (1915–2009), American aerospace engineer
- Thomas O'Malley (disambiguation)
- Tim O'Malley (politician) (born 1944), Irish politician
- Tim O'Malley (rugby union) (born 1994), New Zealand rugby union player
- Tim O'Malley (actor), author of Godshow
- Tom O'Malley (born 1960), former American Major League Baseball player
- Tom O'Malley (American football) (1925–2011), American football player
- Tony O'Malley (1913–2003), Irish painter
- Tuthal Ó Máille (fl.1413], Gaelic-Irish lord
- Walter O'Malley (1903–1979), owner of the Brooklyn/Los Angeles Dodgers baseball team
- William O'Malley (disambiguation)
- Zack O'Malley Greenburg (born 1985), American writer, journalist, and former child-actor
Fictional characters
- Mr. O'Malley, comic strip fairy-godfather
- Conor O'Malley, in dark fantasy drama film "A Monster Calls", directed by J. A. Bayona and written by Patrick Ness
- O'Malley, a fictional character in the machinima series Red vs. Blue
- Abraham de Lacy Giuseppe Casey Thomas O'Malley, from the 1970 Disney animated film The Aristocats
- George O'Malley, from Grey's Anatomy
- Father Charles "Chuck" O'Malley, from the films Going My Way and The Bells of St. Mary, and the TV series Going My Way
- Nellie O'Malley, from American Girl's Samantha sub-series
- Sally O'Malley, a recurring character on Saturday Night Live
- James Redford O'Malley, a side-character appearing in issue six of "The O'Malley Family & Co".