O'Reilly () is a common Irish surname. The O'Reillys were historically the kings of East Bréifne in what is today County Cavan. The clan were part of the Connachta's Uí Briúin Bréifne kindred and were closely related to the Ó Ruairc (O'Rourkes) of West Bréifne. O'Reilly is ranked tenth in the top twenty list of most common Irish surnames. It is also the patronymic form of the Irish name Reilly ().

Naming conventions

Male Daughter Wife (Long) Wife (Short) Ó Raghallaigh Ní Raghallaigh Bean Uí Raghallaigh Uí Raghallaigh

Overview Usually anglicised as Reilly, O'Reilly or Riley, the original form of the name, Ó Raghallaigh, denotes "descendant of Raghallach".

The Ó Raghallaigh family were part of the Connachta, with the eponymous Raghallach said to have died at the Battle of Clontarf in 1014.

The name is common and widespread throughout Ireland, ranked 11th most common in 1890Matheson, Robert E. (1894), Special report on surnames in Ireland, with notes as to numerical strength, derivation, ethnology, and distribution; based on information extracted from the indexes of the General register office. Appendix to the Twenty-Ninth Detailed Annual Report of the Registrar-General of Marriages, Births, and Deaths in Ireland, Dublin: For Her Majesty's Stationery Office by Alexander Thom & Co. (Limited), p. 9 (accessible online) and in 1997.Murphy, Sean J. (2014), A Survey of Irish Surnames 1992–97. In: Studies in Irish Genealogy and Heraldry, Windgates, County Wicklow, pp. 14–29 (first published 2008, last revision 2014), here p. 27 (accessible online)

A self-proclaimed and disputed O'Reilly Clan Chieftain to this day is at odds with the O'Rourke Clan Chieftain because he contests the recognised O'Rourke claim on the title Prince of Breifne.Newerkla, Stefan Michael (2020), Das irische Geschlecht O'Reilly und seine Verbindungen zu Österreich und Russland [The Irish O'Reilly family and their connections to Austria and Russia]. In: Diachronie – Ethnos – Tradition: Studien zur slawischen Sprachgeschichte [Diachrony – Ethnos – Tradition: Studies in Slavic Language History]. Eds. Jasmina Grković-Major, Natalia B. Korina, Stefan M. Newerkla, Fedor B. Poljakov, Svetlana M. Tolstaja. Brno, Tribun EU, pp. 259–279, here 263–265 (accessible online). This was settled in 1994 when the Chief Herald of Ireland made the O'Rourke Chief the Prince of Breifne, but the Office of the Chief Herald stopped granting courtesy titles to Gaelic Chiefs in 2003 (see O'Rourke).

People with the surname

O'Reilly People with the surname O'Reilly include: Alejandro O'Reilly (1722–1794), second Spanish governor of colonial Louisiana Andreas O'Reilly (1742–1832), Irish-born Austrian general Bernard O'Reilly (1903–1975), Australian author, found the wreck of a Stinson aircraft in the McPherson Range, 1937 Bernard O'Reilly (bishop of Hartford) (1803–1856), Irish Roman Catholic bishop Bernard O'Reilly (bishop of Liverpool) (1824–1894), Irish Roman Catholic bishop Bill O'Reilly (born 1949), American commentator and television show host of The O'Reilly Factor on the Fox News Channel Bill O'Reilly, Australian cricketer Bob O'Reilly, Australian rugby league footballer Caitriona O'Reilly, Irish poet and critic Cal O'Reilly, Canadian ice hockey player Cameron O'Reilly, Irish and Australian businessman Cassia O'Reilly, Irish singer-songwriter Charles O'Reilly (died 1800), Roman Catholic Bishop of Kilmore from 1798 to 1800 Danny O'Reilly, lead singer of Irish band, The Coronas David O'Reilly, several people Dermot O'Reilly (1942–2007), Irish-born Canadian singer and songwriter in band Ryan's Fancy, working in Newfoundland and Labrador Des O'Reilly (1954–2016), Australian rugby league player

Emily O'Reilly, Irish journalist Emma O'Reilly, Irish physiotherapist and cycling soigneur who worked for Lance Armstrong Eugenia O'Reilly-Regueiro, Mexican mathematician Finbarr O'Reilly, Canadian photographer Gary O'Reilly, English footballer Genevieve O'Reilly, Irish actress Heather O'Reilly (born 1985), American soccer player Hugh Reily (1630–1695), Irish M.P. and political author James Reilly (Canadian politician) (1835–1909), Canadian businessman and politician from Alberta James O'Reilly, American Roman Catholic priest Jennifer O'Reilly (1943–2016), medieval historian of Britain and Ireland Joe O'Reilly, Irish politician John Reyly (recte O'Reilly) (c. 1646–1717), M.P. for Cavan County in the Parliament of Ireland of 1689 John B. O'Reilly Jr. (1948–2025), American politician from Michigan John O'Reilly (born 1940), Canadian politician from Ontario Kyle O'Reilly (born 1987), ring name of Canadian professional wrestler Kyle Greenwood Leonora O'Reilly, American feminist Luke O'Reilly (disambiguation), several people Mary Margaret O'Reilly, assistant director of the United States Bureau of the Mint from 1924 to 1938 Matthew O'Reilly, Irish politician and farmer Nico O'Reilly, English footballer at Manchester City F.C. O'Reilly, Lords of Bréifne (c. 1161–1607), Irish rulers Patrick Thomas O'Reilly (1833–1892), US Catholic bishop, born in Ireland Peter O'Reilly (civil servant) (1827–1905), Irish-born settler and official in the Colony of British Columbia Peter O'Reilly (hurler) (1902–1940), Irish hurler Philip O'Reilly (Cavan County MP) (c. 1600–1655), M.P. for County Cavan Philip Og O'Reilly (c. 1640–1703), M.P. for Cavan Borough in the Parliament of Ireland of 1689 Philip Reyley (recte O'Reilly) (c. 1630 – after 1689), M.P. for Cavan County in the Parliament of Ireland of 1689 Randall C. O'Reilly (born 1967), American professor of psychology, developer of Leabra Robert O'Reilly (born 1950), American actor Ruth O'Reilly (born 1981), Irish rugby union player Ryan O'Reilly (ice hockey) (born 1991), Canadian ice hockey player Ryan O'Reilly (wrestler) (born 1980), American professional wrestler Sam O'Reilly (born 2006), Canadian ice hockey player Samuel O'Reilly (1854–1909), American tattoo artist and inventor Stephen O'Reilly (born 1964) (better known as Stephen Egerton), American musician Stephen O'Reilly, American actor Stephen O'Reilly, Australian footballer Terry O'Reilly, Canadian hockey player Tim O'Reilly (born 1954), Irish-American founder of O'Reilly Media Tom O'Reilly (1915–1995), Irish Gaelic footballer and politician Tom O'Reilly, Irish Sinn Féin politician Tom O'Reilly, Papua New Guinea international Tony O'Reilly (1936–2024), Irish businessman Valli O'Reilly, American makeup artist Walter Cresswell O'Reilly (1877–1954), Australian Commonwealth Film Censor and founding President of the National Trust of Australia

O'Riley Bunny Wailer (1947–2021), Jamaican reggae musician sometimes known as Bunny O'Riley Christopher O'Riley (born 1956), American classical pianist and public radio show host Don O'Riley (1945–1997), American Major League Baseball pitcher Jon Riley (1824–1879), US army deserter also known as John O'Riley Matt O'Riley (born 2000), English footballer at Brighton FC

Ní Raghallaigh Shónagh Ní Raghallaigh, Irish politician

Riley

Fictional characters with the surname Mr. O'Reilly, portrayed by the Irish actor David Kelly in the Fawlty Towers episode "The Builders" Aloysius Umbongo N'Danga O'Reilly, in the song "Baguette Dilemma for the Booker Prize Guy" by the band Half Man Half Biscuit on their 2014 album Urge for Offal Corporal Walter "Radar" O'Reilly, in the M*A*S*H media franchise Reilly O'Reilly, from the adult animated show John Callahan's Quads!

See also

Riley (disambiguation) Ryley (name) Riley (surname) "Baba O'Riley", a song by The Who

References

External links

The O'Reilly Clan O'Reilly family pedigree at Library Ireland Statistics about O'Reilly Ancestors O'Reilly, Reilly, Riley. History of family Irish Times surname entry for "Riley" The Irish O'Reilly family and their connections to Austria and Russia by Stefan M. Newerkla