O'Brien

Language(s)	Irish
Origin
Derivation	Ó Briain
Meaning	descendant of Brian
Region of origin	Munster, Ireland

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 (plural, Uí Briain). Notable people with the name include:

• Aidan O'Brien (b. 1969), Irish race horse trainer
• Aiden O'Brien, Irish football player
• Alan O'Brien, Irish association football player
• Alex O'Brien (b. 1970), professional American tennis player
• Ambrose O'Brien
• Andy O'Brien (disambiguation), various
• Anne O'Brien (disambiguation), various
• Arthur O'Brien
• Austin O'Brien

• Barry O'Brien
• 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
• Brock O'Brien
• Buck O'Brien
• Burton O'Brien

• Cathy O'Brien (athlete) (b. 1967), American long-distance runner
• Cathy O'Brien (conspiracy theorist) (b. 1957), purported American child-slave/sex-abuse victim
• Charles O'Brien (disambiguation), various
• Christian O'Brien (1914-2001), British geologist, author & historian
• Ciaran O'Brien
• Cinders O'Brien
• Clinton O'Brien (b. 1974), Australian rugby league footballer
• Conal O'Brien
• Conan O'Brien (b. 1963), US comedian and talk show host
• Connor O'Brien (disambiguation)
• Conor O'Brien (disambiguation), various
• Cubby O'Brien

• Daniel O'Brien (disambiguation), various
• Danielle O'Brien
• Danny O'Brien (disambiguation), various
• Dara Ó Briain, Irish comedian and presenter
• Darcy O'Brien (1939–1998), American true crime author
• Daryl O'Brien (b. 1941), Australian footballer (Australian rules football)
• Dave O'Brien (actor) (1912–1969), American film actor
• Dave O'Brien (sportscaster), American sportscaster
• David O'Brien (disambiguation), various
• Doug Brien (born 1970), former American football placekicker
• Don Brien (born 1959), Canadian sprint canoer, who competed in the mid to late 1980s
• Declan O'Brien, president of Utopia Pictures & Television, and a writer and producer
• Declan O'Brien (footballer)
• 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
• Dylan O'Brien (b. 1991), American actor

• 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, Grand Master of the Equestrian Order of the Holy Sepulchre of Jerusalem
• Eileen O'Brien (disambiguation), various
• Elaine O'Brien, American politician
• Erin O'Brien (writer), American writer
• Erin Joanne O'Brien (1934–2021), American actress
• Eugene O'Brien (disambiguation), various

• Fergal O'Brien, Irish professional snooker player
• Fergus O'Brien (1930–2016), Irish politician
• Fitz James O'Brien, Irish born American novelist
• Flann O'Brien, pen name of Irish novelist and satirist Brian O'Nolan

• Gareth O'Brien
• Geraldine O'Brien
• George O'Brien (disambiguation), various
• Ger O'Brien
• Geoffrey O'Brien
• Glenn O'Brien
• Gray O'Brien
• Gavin O'Brien

• Harry O'Brien (changed his name in 2013 to "Heritier Lumumba")
• Harry J. O'Brien
• 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

• Iain O'Brien
• Ian O'Brien
• Ignatius O'Brien, 1st Baron Shandon (1857–1930), Lord Chancellor of Ireland, 1913–1918

• Jack O'Brien (disambiguation), various
• Jake O'Brien (fighter), MMA fighter
• Jake O'Brien (footballer), Irish footballer
• James O'Brien (disambiguation)
• 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)
• Joan O'Brien
• Joe O'Brien (disambiguation), various
• Joey O'Brien
• John O'Brien (disambiguation), various
• Joseph O'Brien (disambiguation), various

• Kate O'Brien (disambiguation)
• Katharine O'Brien
• Katherine O'Brien
• Kathleen O'Brien
• Katie O'Brien, British female tennis player
• Keith O'Brien (1938-2018), Roman Catholic Cardinal Archbishop of Saint Andrews and Edinburgh
• Ken O'Brien
• Kerry O'Brien (disambiguation)
• Kevin O'Brien (disambiguation), various
• Kieran O'Brien
• 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, Irish painter

• Larry O'Brien (1917–1990), American politician
• Larry O'Brien (Canadian politician), Canadian entrepreneur and politician; Mayor of Ottawa, 2006–2010
• Laurence O'Brien
• Lawrence D. O'Brien
• Leighton O'Brien
• Lévis Brien (born 1955), Quebec politician
• Leo O'Brien (disambiguation), various
• Leonora O'Brien, Irish pharmacist and entrepreneur
• Leslie O'Brien
• Liam O'Brien (disambiguation), various
• Lucy O'Brien
• Luke O'Brien

• Margaret O'Brien
• Mariah O'Brien
• Mark O'Brien (disambiguation), various
• Mary Eileen O'Brien, American academic administrator
• Matthew O'Brien (1814-1855), Irish mathematician
• Maureen O'Brien
• Michael O'Brien (disambiguation), various
• Michele O'Brien
• Mick O'Brien (disambiguation), various
• Mike O'Brien (hurler)
• Miles O'Brien (disambiguation), various
• Mollie O'Brien

• Niall O'Brien (disambiguation), various
• Nick O'Brien

• Olivia O'Brien (born 1999), American singer and songwriter

• Paddy O'Brien (disambiguation), various
• Parry O'Brien
• Patricia Salas O'Brien (born 1958), Peruvian sociologist and Minister of Education
• Patrick O'Brien (disambiguation), for people with forename Patrick or Pat
• Pat O'Brien (disambiguation), various
• Paul O'Brien (disambiguation), various
• Peter O'Brien (disambiguation), various
• Phil O'Brien (disambiguation), several people

• Raymond O'Brien, American Roman Catholic priest
• Richard O'Brien (disambiguation), various
• Riley O'Brien, American baseball player
• Robert O'Brien (disambiguation), various
• Rory Brien
• Ron O'Brien (disambiguation), various
• Roy O'Brien

• Scott O'Brien
• Sean O'Brien (disambiguation)
• Sean Patrick O'Brien (1988-2023), American professional wrestling referee
• Shane O'Brien (disambiguation), various
• Shannon O'Brien
• Sicele O'Brien, Irish aviator
• Simon O'Brien (disambiguation), various
• Soledad O'Brien, American television journalist
• Stephen O'Brien, UK conservative politician for Eddisbury
• Stuart O'Brien (1906–2004), American film editor
• Stuart O'Brien (stage) (1833–1883), Australian actor

• 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), American college football 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

• Una O'Brien, British civil servant

• Vincent O'Brien (disambiguation), various
• Virginia O'Brien

• Walter O'Brien, Computer expert and Irish businessman
• Walter A. O'Brien, American Progressive Party politician
• William O'Brien (disambiguation), various
• Willis H. O'Brien (1886–1962), American motion picture special effects pioneer

• Zach O'Brien, professional ice hockey player

• O'Brien Alston (b. 1965), American former football linebacker
• O'Brien Schofield (b. 1987), American former football linebacker
• O'Brien Smith (c. 1756 – 1811), Irish-American political figure

• O'Brien, a character in George Orwell's novel Nineteen Eighty-Four
• Lady Cassandra O'Brien, fictional character, Doctor Who antagonist
• Chloe O'Brian, a fictional character played by actress Mary Lynn Rajskub on the US television series 24
• Graham O'Brien, a companion of the Thirteenth Doctor in the BBC series Doctor Who
• Keiko O'Brien, fictional character, wife of Miles O'Brien in Star Trek: The Next Generation and Deep Space Nine
• Miles O'Brien, a fictional character in Star Trek: The Next Generation and Deep Space Nine
• Sarah O'Brien, a fictional character on the ITV series Downton Abbey
• Shelia O'Brian, a character from the animated TV series Dungeons and Dragons
• Mr. O'Brien, Mrs. O'Brien and Jack O'Brien, fictional characters in The Tree of Life film

• O'Brien dynasty, the royal dynasty who ruled Thomond