Show ContentsO'Conor Surname History

Today's Irish surnames are underpinned by a multitude of rich histories. The name O'Conor originally appeared in Gaelic as Ó Conchobhair, derived from the personal name Conchobhar. 1

Early Origins of the O'Conor family

The surname O'Conor was first found in Connacht. There were six different septs of this famous name scattered throughout Ireland, of which four continue to boast many members. However, the most important O'Connors were those of Connacht, divided into three main branches: O'Conor Don; O'Conor Roe; and O'Conor Sligo.

The Connacht O'Connors were direct descendants of Conchobhar, King of Connacht, who died in 971 AD. Furthermore, this family produced the last two High Kings of Ireland: Turlough O'Connor (1088-1156) and Roderick O'Connor (1116-1196). It was the invasion of Leinster by Roderick O'Conner on behalf of the Prince of West Brefney that caused the King of Leinster, Dermod MacMorough, to flee to England for aid. This resulted in the Strongbow Invasion of 1168, the beginning of English domination over Ireland.

Despite remaining stubbornly Catholic, the O'Connor family continued to maintain their elite position among the Irish nobility throughout the entire period of British dominance.

Early History of the O'Conor family

This web page shows only a small excerpt of our O'Conor research. Another 182 words (13 lines of text) covering the years 1002, 1641, 1652, 1666, 1698, 1710, 1763, 1791, 1838, 1852 and 1906 are included under the topic Early O'Conor History in all our PDF Extended History products and printed products wherever possible.

O'Conor Spelling Variations

Those scribes in Ireland during the Middle Ages recorded names as they sounded. Consequently, in this era many people were recorded under different spellings each time their name was written down. Research on the O'Conor family name revealed numerous spelling variations, including Connor, Conner, Conor, Connors, O'Connor, Connores, Conner, Connar, Connars, O'Connar, O'Conner, Connair, Connairs, Connaire, Connaires, Cawner, Cawners, Caunnor, Cauner, Cauners and many more.

Early Notables of the O'Conor family

Notable amongst the family name at this time was

  • Cabrach O'Conor and Hugh O'Connor, son and grandson of O'Conor Don, took a prominent part in the 1641-1652 wars
  • Charles O'Conor (1710-1791), was Collector of Irish manuscripts; Charles Owen O'Connor (1838-1906), President of the Royal Irish Academy; and Arthur O'Connor (1763-1852), was an United Irishman and ge...

Migration of the O'Conor family

During the 19th century thousands of impoverished Irish families made the long journey to British North America and the United States. These people were leaving a land that had become beset with poverty, lack of opportunity, and hunger. In North America, they hoped to find land, work, and political and religious freedoms. Although the majority of the immigrants that survived the long sea passage did make these discoveries, it was not without much perseverance and hard work: by the mid-19th century land suitable for agriculture was short supply, especially in British North America, in the east; the work available was generally low paying and physically taxing construction or factory work; and the English stereotypes concerning the Irish, although less frequent and vehement, were, nevertheless, present in the land of freedom, liberty, and equality for all men. The largest influx of Irish settlers occurred with Great Potato Famine during the late 1840s. Research into passenger and immigration lists has brought forth evidence of the early members of the O'Conor family in North America: William Conner who settled in Plymouth, arriving on the "Fortune" in 1621; just a year after the "Mayflower," Cornelious Conner, who settled in Exeter in 1650.


Contemporary Notables of the name O'Conor (post 1700) +

  • Charles O'Conor (1804-1884), American lawyer and politician, a candidate in the 1872 U.S. presidential election
  • Herbert Romulus O'Conor (1896-1960), American Democratic Party politician, the 51st Governor of Maryland (1939-1947)
  • Charles O'Conor (1764-1828), Irish priest and historical author
  • Eugene Joseph O'Conor (1835-1912), Irish-born, New Zealand Member of Parliament
  • Denis Maurice O'Conor (1840-1883), Irish politician, Member of Parliament, High Sheriff of Roscommon in 1865
  • Matthew O'Conor (1773-1844), Don of Ballinagare, County Roscommon, Irish historian, the O'Conor Don and de jure King of Connacht
  • Denis O'Conor (1794-1847), the O'Conor Don, Irish nobleman and politician, Member of Parliament for Roscommon (1831-1847), Junior Lord of the Treasury (1846-1847)
  • Charles Owen O'Conor PC (1838-1906), the O'Conor Don, Irish Member of Parliament for Roscommon (1860–1880), Lord Lieutenant of Roscommon (1896–1906)
  • Roderic O'Conor (1860-1940), Irish painter and etcher from Milltown, Castleplunket, County Roscommon
  • John O'Conor (b. 1947), Irish pianist and pedagogue, former director of the Royal Irish Academy of Music, recipient of an Honorary Fellowship by the Royal Irish Academy of Music
  • ... (Another 4 notables are available in all our PDF Extended History products and printed products wherever possible.)


  1. MacLysaght, Edward, The Surnames of Ireland. Ireland: Irish Academic Press, sixth edition, 1985. Print. (ISBN 0-7165-2366-3)


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