O'Brien is a surname of Irish origin. It has many variants in the Irish diaspora worldwide, such as Brien, O'Bryan, O'Brian, Brian, O'Brine and O'Bryen, which all claim a general common ancestry. The original Gaelic surname is Ó Briain (feminine maiden form: Ní Bhriain; plural form and feminine marital form: Uí Bhriain).
Notable people with the name include:
As surname
A Aidan O'Brien (born 1969), Irish racehorse trainer Aiden O'Brien, Irish football player Alan O'Brien, Irish association football player Alex O'Brien (born 1970), American tennis player Ambrose O'Brien (1885–1968), Canadian founder of the National Hockey Association
Anne O'Brien (disambiguation), various Arthur O'Brien (1878–1951), New Zealand rugby union fullback Austin O'Brien (born 1981), American actor and photographer
B Barry O'Brien (born 1957), American TV screenwriter and producer Billy O'Brien (baseball) (1860–1911), American baseball player Billy O'Brien (footballer), Welsh association football player Brendan O'Brien (disambiguation), various Brenna O'Brien (born 1991), Canadian actress and voice actor Brock O'Brien (born 1988), Australian rules footballer with Fremantle Buck O'Brien (1882–1959), pitcher with the Boston Red Sox and the Chicago White Sox Burton O'Brien (born 1981), Scottish football player
C Casey O'Brien (b. 2001), American ice hockey player Cathy O'Brien (athlete) (b. 1967), American long-distance runner Cathy O'Brien (conspiracy theorist) (b. 1957), American purported child-abuse victim Cecily O'Bryen (1899–1984), British diving champion Charles O'Brien (disambiguation), various Christian O'Brien (1914–2001), British geologist, author & historian Ciaran O'Brien (born 1987), American soccer coach and player Cinders O'Brien, John F., or Darby O'Brien (1867–1892), American baseball pitcher Clinton O'Brien (born 1974), Australian rugby league footballer Conal O'Brien (born 1956), American television director Conan O'Brien (born 1963), US comedian and talk show host Connor O'Brien (disambiguation) or Conor O'Brien (disambiguation), various people Cubby O'Brien (born 1946), American drummer and original Mouseketeer
D Daniel O'Brien (disambiguation), various Danielle O'Brien (born 1990), Australian ice dancer Danny O'Brien (disambiguation), various Darcy O'Brien (1939–1998), American true crime author Daryl O'Brien (b. 1941), Australian rules footballer Dave O'Brien (actor) (1912–1969), American film actor Dave O'Brien (sportscaster), American sportscaster David O'Brien (disambiguation), various Doug Brien (born 1970), American football placekicker Don Brien (born 1959), Canadian sprint canoer Declan O'Brien (1965–2022), American film and TV writer and producer Declan O'Brien (footballer) (born 1979), with Drogheda United Dennis O'Brien (disambiguation), various Derek O'Brien (disambiguation), various Dermod O'Brien (1865–1906), Irish painter Donald O'Brien (disambiguation), various Doug O'Brien (born 1984), Canadian ice hockey defenceman Dylan O'Brien (b. 1991), American actor
E Ed O'Brien (b. 1968), English musician Edmond O'Brien (1915–1985), American actor Edna O'Brien (1930–2024), Irish novelist Edward O'Brien (disambiguation), various Edwin Frederick O'Brien (born 1939), American Catholic prelate Eileen O'Brien (disambiguation), various Elaine O'Brien (1955–2014), American politician Erin O'Brien (writer), American writer Erin Joanne O'Brien (1934–2021), American actress Eugene O'Brien (disambiguation), various
F Fergal O'Brien (born 1872), Irish professional snooker player Fergal O'Brien (trainer) (born 1972), Irish National Hunt trainer Fergus O'Brien (1930–2016), Irish politician Fitz James O'Brien (1826–1862), American SF and fantasy writer Flann O'Brien (Brian O'Nolan, 1911–1966), Irish novelist and satirist
G Gareth O'Brien (born 1991), English rugby league footballer Geraldine O'Brien (1922–2014), Irish botanical illustrator George O'Brien (disambiguation), various Ger O'Brien (born Gerard O'Brien, 1984), Irish footballer Gerard O'Brien (disambiguation), various Geoffrey O'Brien (born 1948), American poet, editor, and film critic Glenn O'Brien (1947–2017), American writer, "The Style Guy" Gray O'Brien (born Gerard O'Brien, 1968), Scottish actor Gavin O'Brien (born 1993), Irish hurler
H Harry O'Brien, later Héritier Lumumba (born 1986), Australian rules footballer Harry J. O'Brien "Shorty" (1884–1955), American football, basketball, baseball coach Helen O'Brien (1925–2005), British nightclub owner and spy Henry O'Brien (disambiguation), various Hod O'Brien (1936–2016), American jazz pianist Hugh O'Brien (1827–1895), mayor of Boston
I Iain O'Brien (born 1976), New Zealand cricketer Ian O'Brien (born 1947), Australian breaststroke swimmer Ignatius O'Brien, 1st Baron Shandon (1857–1930), Lord Chancellor of Ireland, 1913–1918
J Jack O'Brien (disambiguation), various Jake O'Brien (ice hockey) (born 2007), Canadian ice hockey player Jake O'Brien (fighter) (born 1984), American MMA fighter Jake O'Brien (footballer) (born 2001), Irish footballer James O'Brien (disambiguation), various Jamie O'Brien (disambiguation), various Jeremiah O'Brien (1744–1818), US Navy officer of the American Revolutionary War Jesse O'Brien (disambiguation), various Jim O'Brien (disambiguation), various Joan O'Brien (1936–2025), American actress and singer Joanne O'Brien, portrait and documentary photographer Joe O'Brien (disambiguation), various Joey O'Brien (born 1986), Irish football player John O'Brien (disambiguation), various Joseph O'Brien (disambiguation), various
K Kate O'Brien (disambiguation) Katharine O'Brien, American film director Katharine O'Brien (disambiguation), other people of that name Katherine O'Brien (born 1963), Canadian pediatric infectious disease physician Kathleen O'Brien (1914–1991), Australian illustrator and fashion artist Katie O'Brien, British tennis player Keith O'Brien (1938–2018), Scottish Roman Catholic prelate Ken O'Brien (born 1960), American football quarterback Kerry O'Brien (disambiguation), various Kevin O'Brien (disambiguation), various Kieran O'Brien (born 1973), English actor Kim O'Brien, American film and television actress Kirsten O'Brien (born 1972), British TV presenter Kitt O'Brien (born 1990), American football player Kitty Wilmer O'Brien (1910–1982), Irish landscape painter
L Larry O'Brien (1917–1990), American politician Larry O'Brien (Canadian politician) (born 1949), businessman, mayor of Ottawa Laurence O'Brien (1792–1870), Irish merchant and politician in Newfoundland Lawrence O'Brien (disambiguation), various Lawrence D. O'Brien (1951–2004), Canadian politician representing Labrador Leighton O'Brien (born 1976), American soccer player with the Seattle Sounders Lévis Brien (born 1955), Quebec politician Leo O'Brien (disambiguation), various Leonora O'Brien, Irish pharmacist and entrepreneur Leslie O'Brien (1908–1995), Governor of the Bank of England Leslie O'Brien (cricketer) (1905–1967), played for New South Wales Liam O'Brien (disambiguation), various Lucy O'Brien (born 1961), writer on women in music Lucy O'Brien (philosopher) (born 1964), at University College, London Lucy O'Brien (doctor) (1923–2006), Irish missionary in Africa Luke O'Brien (born 1988), English footballer with Bradford City
M Margaret O'Brien (born 1937), American actress Margaret O'Brien (politician) (born 1973), Michigan Republican Maria O'Brien (actress) (1950–2026), American actress and acting coach Mariah O'Brien (born 1971), American actress and interior designer Mark O'Brien (disambiguation), various Mary Eileen O'Brien, American academic administrator Matthew O'Brien (mathematician) (1814–1855), Irish mathematician Maureen O'Brien (born 1943), English actress in the Doctor Who series Michael O'Brien (disambiguation), various Michele O'Brien (born 1980), soccer coach and player for Chicago Red Eleven Mick O'Brien (disambiguation), various Mike O'Brien (hurler) (born 2011) with Glenroe and Limerick Miles O'Brien (disambiguation), various Mollie O'Brien (born 1952), a folk singer from West Virginia
N Niall O'Brien (disambiguation), various Natasha O'Brien, an Irish woman attacked by an active-duty Irish soldier Nick O'Brien (born 1993), Australian rules footballer for Essendon
O Olivia O'Brien (born 1999), American singer and songwriter
P Paddy O'Brien (disambiguation), various Parry O'Brien (1932–2007), American shot put champion Patricia Salas O'Brien (born 1958), Peruvian sociologist and Minister of Education Patrick O'Brien (disambiguation), for people with the forename Patrick or Pat Pat O'Brien (disambiguation), various Paul O'Brien (disambiguation), various Peter O'Brien (disambiguation), various Phil O'Brien (disambiguation), various
R Raymond O'Brien (born 1944), American Roman Catholic priest Raymond Moulton O'Brien (1905–1977), British-born American businessman Richard O'Brien (disambiguation), various Riley O'Brien (born 1995), American baseball pitcher Robert O'Brien (disambiguation), various Ron O'Brien (disambiguation), various Roy O'Brien (born 1974), Irish football player
S Saylor O'Brien (born 2003), American para-alpine skier Scott O'Brien (born 1957), American football player, coach and scout Sean O'Brien (disambiguation) Sean Patrick O'Brien (1988–2023), American professional wrestling referee Shane O'Brien (disambiguation), various Shannon O'Brien (disambiguation), various Sicele O'Brien (1887–1931), Irish woman aviation pioneer Simon O'Brien (disambiguation), various Soledad O'Brien (born 1966), American woman television journalist Stephen O'Brien (born 1957), UK conservative politician for Eddisbury Stuart O'Brien (1906–2004), American film editor Stuart O'Brien (stage) (1833–1883), Australian actor
T Terence O'Brien (disambiguation), various Thomas O'Brien (disambiguation), various Tim O'Brien (disambiguation), various Timothy O'Brien (theatre designer) (1929–2022), British theatre designer Timothy O'Brien (endocrinologist), Irish professor Timothy L. O'Brien (born 1961), American journalist Tina O'Brien (born 1983), English actress Tom O'Brien (actor) (b. 1965), American film actor Tom O'Brien (American football) (b. 1948), coach at North Carolina State University Tom O'Brien (outfielder) (1873–1901), baseball outfielder Tom O'Brien (second baseman) (1860–1921), 19th-century baseball player Tom O'Brien (trade unionist) (1900–1970), British trade unionist and Member of Parliament Tommy O'Brien (baseball) (1918–1978), baseball outfielder
U Una O'Brien, British civil servant
V Vincent O'Brien (disambiguation), various Virginia O'Brien (1919–2001), American actress and comic, "Frozen Face" singer
W Walter O'Brien (born 1975), Irish businessman and computer specialist Walter A. O'Brien (1914–1998), American Progressive Party politician William O'Brien (disambiguation), various Willis H. O'Brien (1886–1962), American motion picture special effects pioneer
Z Zach O'Brien (born 1992), professional ice hockey player
Irish Gaelic surname
Aoife Ní Bhriain, Irish violinist Doireann Ní Bhriain (born 1952), Irish radio producer Eibhlín Ní Bhriain (1925–1986), Irish journalist Dara Ó Briain (born 1972), Irish comedian and presenter Donnchadh Ó Briain (1897–1981), Irish politician Liam Ó Briain (1888–1974), Irish linguist Niamh Uí Bhriain (born 1970), Irish lobbyist and campaigner
As first or middle names O'Brien Alston (b. 1965), American former football linebacker O'Brien Schofield (b. 1987), American former football linebacker O'Brien Smith (–1811), Irish-American political figure
Fictional characters O'Brien, a character in George Orwell's novel Nineteen Eighty-Four Lady Cassandra O'Brien, a fictional character, Doctor Who antagonist