O'Callaghan History, Family Crest & Coats of Arms 

Origins Available: 
  Ireland 


Before Irish names were translated into English, O'Callaghan had a Gaelic form of Ó Ceallachain, possibly from "ceallach", which means "strife". The family is descended from Ceallachan (Callaghan), the 10th century King of Munster from whom their surname is derived, and as such, the name O'Callaghan is a patronymic name. 1

Early Origins of the O'Callaghan family

The surname O'Callaghan was first found in Munster. The earliest mention of the name O'Callaghan placed them in the barony of Kinlea, in County Cork, yet the family lost most of their original lands in the barony of Kinelea during the Anglo-Norman Conquest under Strongbow. They relocated to an area near Mallow, in the north of the county, and remained there until forced off their lands once again during the Cromwellian Invasion of the 17th century.

The head family migrated to the east of County Clare and flourished, giving their name to the village of Callaghan's Mills. The resumption of the often-discarded prefix "O" has been widespread during the late twentieth century, but in the early twentieth century, Callaghans greatly outnumbered O'Callaghans, but such is no longer the case. The O'Callaghans are one of the few Irish families to still have a chief, certified by the Genealogical Office. 2

Early History of the O'Callaghan family

This web page shows only a small excerpt of our O'Callaghan research. Another 202 words (14 lines of text) covering the years 1172, 1605, 1640, 1654, 1738, 1797, 1807, 1839, 1883 and 1909 are included under the topic Early O'Callaghan History in all our PDF Extended History products and printed products wherever possible.

O'Callaghan Spelling Variations

The general population of Ireland, like those of Europe and Britain during the Middle Ages, scribes recorded people's names as they saw fit. As a result, surnames often had many spelling variations. For O'Callaghan some of these variations included: Callaghan, Callahan, O'Callaghan, O'Callahan, Calahan, Cellaghan, Kalahan, Kallaghan, Kallahan, O'Kallaghan, Kellaghan, Kelleghan, Kellahan, Kelahan, Ceilahan, Ceilaghan, Callachan, Calachan, Callagan, Calagan, Kelagan, Callighan and many more.

Early Notables of the O'Callaghan family

Notable among the family name at this time was

O'Callaghan Ranking

In the United States, the name O'Callaghan is the 11,990th most popular surname with an estimated 2,487 people with that name. 3 However, in Australia, the name O'Callaghan is ranked the 862nd most popular surname with an estimated 4,600 people with that name. 4



O'Callaghan migration to the United States +

The 18th and 19th centuries saw many Irish families immigrate to North America in search of land and opportunities. The largest influx of Irish immigrants to the United States and British North America came during the 1840s when the Great Potato Famine laid waste to their homeland. Hundreds of thousands left the island in an attempt to escape the starvation and disease it brought. Although the arrival of such a large number of destitute Irish was not welcomed by the established population in the United States and what would become known as Canada at the time, these Irish were an essential element to the rapid development of these growing industrial nations. They filled the demand for the cheap labor needed for the work in factories and in the construction of bridges, roads, canals, and railways. An examination of passenger and immigration lists has revealed many immigrants bearing the name of O'Callaghan or one of its variants:

O'Callaghan Settlers in United States in the 19th Century

O'Callaghan migration to Australia +

Emigration to Australia followed the First Fleets of convicts, tradespeople and early settlers. Early immigrants include:

O'Callaghan Settlers in Australia in the 19th Century

O'Callaghan migration to New Zealand +

Emigration to New Zealand followed in the footsteps of the European explorers, such as Captain Cook (1769-70): first came sealers, whalers, missionaries, and traders. By 1838, the British New Zealand Company had begun buying land from the Maori tribes, and selling it to settlers, and, after the Treaty of Waitangi in 1840, many British families set out on the arduous six month journey from Britain to Aotearoa to start a new life. Early immigrants include:

O'Callaghan Settlers in New Zealand in the 19th Century

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






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