Find out how popular the last name O'Brien 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'Brien.

O'Brien, 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'Brien surname is from the 2010 census data.

Popularity of O'Brien in America

O'Brien is the 11031st most popular name in America based on the data we have collected from the U.S. Census Bureau.

The O'Brien surname appeared 2,882 times in the 2010 census and if you were to sample 100,000 people in the United States, approximately 1 people would have the surname O'Brien.

We can also compare 2010 data for O'Brien 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'Brien

The surname Brien has its origins in Ireland, where it is thought to have first emerged in the 12th century. It is derived from the old Gaelic word "bran," which means "raven" or "crow." This suggests that the name may have been initially given as a nickname to someone with dark hair or a swarthy complexion.

One of the earliest recorded instances of the name Brien can be found in the Annals of Ulster, a chronicle of medieval Irish history dating back to the 15th century. The annals mention a chieftain named Aedh Bren who ruled over a territory in what is now County Galway in the late 12th century.

In the 16th century, the name Brien appeared in the Fiants of the Tudor Conquest, a collection of official documents from the English conquest of Ireland. These records mention several individuals with the surname, including Dermot O'Brien, who was granted lands in County Clare in 1584.

The Brien family was particularly prominent in County Clare and County Limerick during the 16th and 17th centuries. One notable figure from this era was Connor O'Brien, the 3rd Earl of Thomond, who was born in 1534 and played a significant role in the Elizabethan wars in Ireland.

Another famous bearer of the name was William Brien, an Irish soldier and writer who was born in 1685 and served in the armies of several European countries, including France and Austria. He is best known for his memoirs, which provide valuable insights into the life of an Irish soldier of fortune in the 18th century.

In the 19th century, the Brien surname was often anglicized to "Bryan" or "Bryant," particularly among those who emigrated to English-speaking countries like the United States and Canada. One prominent individual with this spelling was William Jennings Bryan, an American politician and orator who ran for president three times and was born in 1860.

Throughout its history, the Brien name has been associated with various place names in Ireland, such as Briensville in County Westmeath and Briensborough in County Kilkenny. These localities likely derived their names from influential Brien families who resided or held lands in those areas.

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

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

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'Brien 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'Brien 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'Brien 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'Brien, please contact us.

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