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O'Callaghan History Etymology Early Origins Early History Spelling Variations Early Notables Ranking

Contemporary Notables Historic Events Related Stories Citations

O'Callaghan History, Family Crest & Coats of Arms

Origins Available:
Ireland

Etymology of O'Callaghan

What does the name O'Callaghan mean?

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

Abbé John O'Callaghan (1605-1654), prominent Jansenist in France

O'Callaghan Ranking

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

Minnie O'Callaghan, aged 28, Irish settler who arrived in New York aboard the ship "Baltic" 5

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

Maria O'Callaghan, aged 17, Irish settler who arrived in New York aboard the ship "Palmyra" in 1819 5
Anna O'Callaghan, aged 21, Irish settler who arrived in New York aboard the ship "Palmyra" in 1819 5
Denis O'Callaghan, aged 2, Irish settler who arrived in New York aboard the ship "Palmyra" in 1819 5
Jas T. O'Callaghan, aged 30, Irish settler who arrived in New York aboard the ship "Palmyra" in 1819 5
Johanna O'Callaghan, aged 2, Irish settler who arrived in New York aboard the ship "Palmyra" in 1819 5
... (More are available in all our PDF Extended History products and printed products wherever possible.)

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

Thomas O'Callaghan, aged 21, a farm labourer, who arrived in South Australia in 1850 aboard the ship "Joseph Soames" 6
Johanna O'Callaghan, aged 23, a servant, who arrived in South Australia in 1850 aboard the ship "Joseph Soames" 6
Margaret O'Callaghan, aged 18, a servant, who arrived in South Australia in 1850 aboard the ship "Joseph Soames" 6
John O'Callaghan, aged 21, who arrived in South Australia in 1854 aboard the ship "Sir Thomas Gresham" 7
Patrick O'Callaghan, aged 27, who arrived in South Australia in 1854 aboard the ship "Sir Thomas Gresham" 7
... (More are available in all our PDF Extended History products and printed products wherever possible.)

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

W. P. G. O'Callaghan, who arrived in Auckland, New Zealand aboard the ship "Queen of Beauty" in 1863
Arthur O'Callaghan, who arrived in Auckland, New Zealand aboard the ship "Talbot" in 1864
Arthur O'Callaghan, who arrived in Auckland, New Zealand aboard the ship "Glendevon" in 1864
Margaret O'Callaghan, aged 27, a housemaid, who arrived in Wellington, New Zealand aboard the ship "Gainsborough" in 1878 8
Jeremiah O'Callaghan, aged 20, a farm labourer, who arrived in Wellington, New Zealand aboard the ship "Rakaia" in 1878
... (More are available in all our PDF Extended History products and printed products wherever possible.)

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

Lieutenant-General William O'Callaghan DSM (1921-2015), Irish Army officer, Commanding Officer of the United Nations Interim Force in Lebanon
Conor O'Callaghan (b. 1968), Irish poet
Eugene O'Callaghan (1888-1973), Irish priest in the Archdiocese of Armagh
Professor Kathleen "Kate" O'Callaghan (1888-1961), Irish Sinn Féin politician and academic
Gareth O'Callaghan, Irish author, radio presenter and former television presenter
David O'Callaghan, Irish hurler and former Gaelic football player
Mollie Grace O'Callaghan OAM, Australian swimmer, two gold and one bronze medals at the 2020 Summer Olympics, and two-time gold medalist at the 2024 Summer Olympics
Joseph O'Callaghan SJ (1824-1869), American Catholic priest and Jesuit, born in Massachusetts, he studied in Canada and then at the College of the Holy Cross before entering the Society of Jesus in 1844
Gary Bernard O'Callaghan MBE (b. 1933), Australian radio announcer based in Sydney, Australian Commercial Radio Hall of Fame recipient
Eugene "Taffy" Oâ€™Callaghan (1906-1946), Welsh professional footballer
... (Another 5 notables are available in all our PDF Extended History products and printed products wherever possible.)

Historic Events for the O'Callaghan family +

USS Indianapolis

Del Roger O'Callaghan, American crew member on board the ship "USS Indianapolis" when she was on a top secret trip for the first nuclear weapon, she was sunk by Japanese Navy on 30th July 1945, he was one of the many who were killed in the sinking due to exposure, dehydration, saltwater poisoning and shark attacks 9

Citations +

MacLysaght, Edward, The Surnames of Ireland. Ireland: Irish Academic Press, sixth edition, 1985. Print. (ISBN 0-7165-2366-3)
MacLysaght, Edward, Irish Families Their Names, Arms and Origins 4th Edition. Dublin: Irish Academic, 1982. Print. (ISBN 0-7165-2364-7)
"What are the 5,000 Most Common Last Names in the U.S.?". NameCensus.com, https://namecensus.com/last-names/
"Most Common Last Names in Australia." Forebears, https://forebears.io/australia/surnames
Ellis Island Search retrieved 21st October 2021. Retrieved from https://heritage.statueofliberty.org/passenger-result
State Records of South Australia. (Retrieved 2010, November 5) JOSEPH SOMES / SOAMES 1850. Retrieved http://www.slsa.sa.gov.au/BSA/1850JosephSomes.htm
South Australian Register Monday 20th March 1854. (Retrieved 2010, November 5) Sir Thomas Gresham 1854. Retrieved http://www.theshipslist.com/ships/australia/sirthomasgresham1854.shtml
New Zealand Yesteryears Passenger Lists 1800 to 1900 (Retrieved 3rd November 2011). Retrieved from http://www.yesteryears.co.nz/shipping/passlist.html
Final Crew List, retrieved 2021, October 30th Retrieved from https://www.ussindianapolis.com/final-crew