Find out how popular the last name O'Leary is in the United States and learn more about the meaning, history, and race and ethnic origin of people in America who are named O'Leary.

O'Leary, like all of the last names we have data for, is identified by the U.S. Census Bureau as a surname which has more than 100 occurrences in the United States in the Decennial Census survey. The most recent statistics we have for the O'Leary surname is from the 2010 census data.

Popularity of O'Leary in America

O'Leary is the 1607th most popular name in America based on the data we have collected from the U.S. Census Bureau.

The O'Leary surname appeared 22,329 times in the 2010 census and if you were to sample 100,000 people in the United States, approximately 8 people would have the surname O'Leary.

We can also compare 2010 data for O'Leary to data from the previous census in 2000. The table below contains all of the statistics for both years in a side-by-side comparison.

The history of the last name O'Leary

The surname O'Leary is an ancient Irish Gaelic name that originated in County Cork, Ireland. It is derived from the Irish Gaelic words 'O Laoghaire', meaning 'descendant of Laoghaire'. Laoghaire was a popular personal name in ancient Ireland, stemming from the word 'laogh' meaning 'calf' or 'wether'.

The O'Leary name has a long and distinguished history in Ireland, with many references to notable figures bearing the name in ancient texts and manuscripts. One of the earliest recorded mentions of the O'Leary name can be found in the Annals of Inisfallen, a chronicle of medieval Irish history, dating back to the 12th century.

The O'Leary clan was one of the most powerful and influential families in the medieval Kingdom of Desmond, which encompassed much of what is now County Cork and parts of neighboring counties. They held vast estates and played a significant role in the political and military affairs of the region during this period.

One of the most renowned members of the O'Leary family was Donal Cam O'Leary (1577-1660), a distinguished Irish Catholic priest and historian. He was a prominent figure during the Irish Confederate Wars of the 1640s and is best known for his work, the "Remonstrances of the Irish Catholics", which defended the rights of Irish Catholics during the turbulent period.

Another notable O'Leary was Arthur O'Leary (1729-1802), an Irish Franciscan friar and author. He is remembered for his work "An Interesting Tragi-Comic Pastoral Farce", a satirical play that lampooned the Protestant Ascendancy in Ireland.

In the realm of literature, Ellen O'Leary (1831-1889) was a celebrated Irish poet and storyteller. She is best known for her collection of folk tales and stories, which helped to preserve and promote the rich cultural heritage of Ireland.

The O'Leary name has also been carried by individuals who have made significant contributions in various fields, such as Matthew O'Leary (1913-1992), an American judge and politician who served as a member of the United States House of Representatives.

While the O'Leary name has a rich and storied history in Ireland, it has also spread to other parts of the world through emigration. Today, people bearing the O'Leary surname can be found in countries like the United States, Canada, Australia, and New Zealand, where descendants of Irish emigrants have settled and thrived.

Race and ethnic origin of people with the last name O'Leary

We also have some data on the ancestry of people with the surname O'Leary.

The below race categories are the modified race categories used in the Census Bureau's population estimates program. All people were categorized into six mutually exclusive racial and Hispanic origin groups:

1. White only
2. Black only
3. American Indian and Alaskan Native only
4. Asian and Pacific Islander only
5. Hispanic
6. Two or More Races

For the most recent 2010 census data, the race/ethnic origin breakdown for O'Leary was:

Note: Any fields showing (S) means the data was suppressed for privacy so that the data does not in any way identify any specific individuals.

Since we have data from the previous census in 2000, we can also compare the values to see how the popularity of O'Leary has changed in the 10 years between the two census surveys.

Data source

The last name data and ethnic breakdown of last names is sourced directly from the Decennial Census survey, conducted every 10 years by the United States Census Bureau.

The history and meaning of the name O'Leary was researched and written by our team of onomatology and genealogy experts.

If you have a correction or suggestion to improve the history of O'Leary, please contact us.

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