Last Name O-leary

Learn more about the origin of the last name O-leary

The meaning and origin of the last name O-leary

The surname O'Leary is an Irish name derived from the Gaelic "Ó Laoghaire," which translates to "descendant/male progeny of Laoghaire." Laoghaire, also spelled as Lochlann or Laurence in English, was a prominent Irish king and high-king of Munster in the 5th century. The O'Leary clan originated from County Cork in Ireland and were traditionally chieftains of the region known as Muskerry. Over time, the name has evolved with some variations such as O'Leary, Leary, and even O'Laree, all derived from the original Gaelic form "Ó Laoghaire." It is one of the most common surnames in Ireland, particularly among those with Irish ancestry.

Geographical distribution of the last name O-leary

The surname O'Leary is predominantly of Irish origin and is most commonly found in County Cork in the southwest region of Ireland. It is one of the country's principal sept names, signifying that it was once associated with a particular tribe or clan. However, due to emigration, particularly during the 19th century, O'Leary has become a widespread name among Irish communities worldwide, notably in the United States, Canada, Australia, and the United Kingdom. In the U.S., the highest concentrations of O'Learys are found in states like Massachusetts, New York, and California. The name is also prevalent in other English-speaking countries due to historical ties with Ireland and the Irish diaspora.

Variants and spellings of the last name O-leary

The surname O'Leary has various spellings due to its Irish Gaelic origin, which includes the use of an "O" prefix indicating descendance from a male named Leary. Some common variations and spelling formats include:

* O'Leary
* Leary
* O'Learie
* O'Leray
* O'Lery
* Olearie
* Oleray
* Oley
* Oleaire
* Olairey

The Irish language has unique spelling rules, such as the omission of the letter "h" when not pronounced (as in the name Leary), and the use of the "O" prefix, which is often dropped or altered when transliterated into English. These variations can make tracing family history challenging but are an interesting aspect of Irish cultural heritage.

Famous people with the last name O-leary

Notable individuals with the surname O'Leary include:

1. Anita O'Brien (Anita Mae Dixon O'Leary), an American actress and singer who had a successful career in the 1940s and 1950s, best known for her role as Vicki Lane on the radio show "One Man's Family."
2. Denise O'Leary, an English singer-songwriter and actress, who found success in the 1980s with hits like "I Could Never Miss You More" and appearances in several British soap operas.
3. Gerry O'Leary, a Canadian ice hockey goaltender who played professionally for the Toronto Maple Leafs and Boston Bruins during the 1950s and 1960s.
4. Kevin O'Leary (born Patrick Kevin O'Leary), also known as "Mr. Wonderful," is a Canadian businessman, author, and television personality, best known for his role as a judge on the reality TV show "Shark Tank."
5. Michael O'Leary, the CEO of Ryanair, the Irish low-cost airline, has gained notoriety for his often controversial and outspoken approach to business management.
6. Thomas Francis O'Leary (1830–1907), also known as Pádraig Ó Laoghaire, was an Irish Fenian leader and politician who played a significant role in the Irish nationalist movement of the late 19th century.

Genealogical research on the last name O-leary

The surname O'Leary is an anglicized form of the Irish Gaelic name Ó Laoghaire, originating from County Cork, Ireland. The name is derived from the personal name Laoghaire, which means "famous warrior" or "hale warrior". The O'Learys were a prominent and powerful sept that ruled much of west Munster and parts of north Kerry for over 1,000 years before the Anglo-Norman invasion in the late 12th century. After the Norman conquest, the O'Learys became known as the Kings of Desmond and continued to hold significant political and military power until their defeat by Elizabeth I's forces in 1583. The O'Leary clan spread across Ireland and later emigrated to other countries, especially during the Great Famine in the mid-19th century. Today, the surname O'Leary is quite common among the Irish diaspora worldwide.

Last name distribution maps

Sources & References

• INSEE statistics on the surname "O-leary"
• Global distribution of the surname on Forebears.io
• Wikipedia Article

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NomOrigine Team
Passionate about genealogy, name history, and linguistics, we have been analyzing the origins of names for over 3 years. Our content is based on verified historical, etymological, and statistical data.
Last updated : 23 July 2025