Show ContentsCostelloe History, Family Crest & Coats of Arms

The Costelloe surname came to Ireland with the Anglo-Norman invasion of the 12th century. They were originally from the Norman family Nangles, or de Angulos, and descended in Ireland from Gilbert de Nangle. Costello and associated variations come from the personal name of a son of Gilbert, Oisdealbhach, whose name consists of the elements "os," which means "deer or fawn", and "dealbhadh," which means "in the form of" or "resembling." The Gaelic form of the surname Costelloe, which predated the Anglicized version of the name, is Mac Oisdealbhaigh. This is the earliest recorded example of a Norman family assuming a Mac surname. The prefix O has sometimes been erroneously assumed.

Early Origins of the Costelloe family

The surname Costelloe was first found in County Mayo (Irish: Maigh Eo) located on the West coast of the Republic of Ireland in the province of Connacht, where they were granted lands by the Earl of Pembroke in the Anglo-Norman invasion of 1172.

Early History of the Costelloe family

This web page shows only a small excerpt of our Costelloe research. Another 138 words (10 lines of text) covering the years 1172, 1500, 1531, 1567, 1571, 1579, 1606, 1803 and 1865 are included under the topic Early Costelloe History in all our PDF Extended History products and printed products wherever possible.

Costelloe Spelling Variations

Medieval scribes and church officials spelt names simply the way they sounded, which explains the various name spelling variations of the name Costelloe that were encountered when researching that surname. The many spelling variations included: Costello, MacCostello, Costillo, Costallo, Kostello, McCostello, Caustello, Costellow and many more.

Early Notables of the Costelloe family

Notable amongst the family up to this time was Guillauame Costeley (1531-1606), Scottish organist and 'valet du chambre du roy' to Henry II and Charles IX of France. [1] Arthur Dudley Costello (1803-1865), was an English-born Irish novelist and travel writer.William Costeley was a Scottish musician, born 1531, settled in France, and was organist to Henri II and Charles IX. Author of a treatise called...
Another 65 words (5 lines of text) are included under the topic Early Costelloe Notables in all our PDF Extended History products and printed products wherever possible.


United States Costelloe migration to the United States +

A great number of Irish families left their homeland in the late 18th century and throughout the 19th century, migrating to such far away lands as Australia and North America. The early settlers left after much planning and deliberation. They were generally well off but they desired a tract of land that they could farm solely for themselves. The great mass of immigrants to arrive on North American shores in the 1840s differed greatly from their predecessors because many of them were utterly destitute, selling all they had to gain a passage on a ship or having their way paid by a philanthropic society. These Irish people were trying to escape the aftermath of the Great Potato Famine: poverty, starvation, disease, and, for many, ultimately death. Those that arrived on North American shores were not warmly welcomed by the established population, but they were vital to the rapid development of the industry, agriculture, and infrastructure of the infant nations of the United States and what would become Canada. Early passenger and immigration lists reveal many Irish settlers bearing the name Costelloe:

Costelloe Settlers in United States in the 19th Century
  • Ellen Costelloe, aged 20, who arrived in New York in 1854 [2]
  • Josh Costelloe, aged 20, who landed in New York in 1854 [2]

Australia Costelloe migration to Australia +

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

Costelloe Settlers in Australia in the 19th Century
  • Mr. William Costelloe, (b. 1823), aged 22, Irish shoe maker who was convicted in Antrim, Ireland for 7 years for larceny, transported aboard the "Elizabeth and Henry" on 15th February 1845, arriving in Tasmania (Van Diemen's Land) [3]

New Zealand Costelloe 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:

Costelloe Settlers in New Zealand in the 19th Century
  • Catherine Costelloe, who arrived in Lyttelton, New Zealand aboard the ship "Blairgowrie" in 1875
  • Bridget Costelloe, who arrived in Lyttelton, New Zealand aboard the ship "Blairgowrie" in 1875

Contemporary Notables of the name Costelloe (post 1700) +

  • John A. Costelloe (1961-2008), American actor, best known for his role as Jim "Johnny Cakes" Witowski in the HBO TV series The Sopranos
  • John Costelloe (b. 1900), Irish shopkeeper and Fianna Fáil politician
  • Noel Costelloe, Irish sportsperson
  • John Costelloe, Irish politician
  • Paul Costelloe, Irish designer and artist
  • Timothy John Costelloe (b. 1954), Australian metropolitan bishop, 9th Roman Catholic Archbishop of the Archdiocese of Perth, Western Australia (2012-)


The Costelloe Motto +

The motto was originally a war cry or slogan. Mottoes first began to be shown with arms in the 14th and 15th centuries, but were not in general use until the 17th century. Thus the oldest coats of arms generally do not include a motto. Mottoes seldom form part of the grant of arms: Under most heraldic authorities, a motto is an optional component of the coat of arms, and can be added to or changed at will; many families have chosen not to display a motto.

Motto: Ne te quaesiveris extra
Motto Translation: Seek nothing beyond your sphere.


  1. Smith, George (ed), Dictionary of National Biography. London: Smith, Elder & Co., 1885-1900. Print
  2. Filby, P. William, Meyer, Mary K., Passenger and immigration lists index : a guide to published arrival records of about 500,000 passengers who came to the United States and Canada in the seventeenth, eighteenth, and nineteenth centuries. 1982-1985 Cumulated Supplements in Four Volumes Detroit, Mich. : Gale Research Co., 1985, Print (ISBN 0-8103-1795-8)
  3. Convict Records Voyages to Australia (Retrieved 11th March 2022). Retrieved from https://convictrecords.com.au/ships/elizabeth-and-henry


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