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

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

Popularity of O'Riordan in America

O'Riordan is the 33810th most popular name in America based on the data we have collected from the U.S. Census Bureau.

The O'Riordan surname appeared 673 times in the 2010 census and if you were to sample 100,000 people in the United States, approximately 0 people would have the surname O'Riordan.

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

The surname ORIORDAN is of Irish origin, originating from the County Cork region of Ireland. It dates back to the 12th century and is derived from the Irish Gaelic words "O Riordain," which translates to "descendant of Riordan." The prefix "O" was commonly used to denote a grandson or descendant in Irish surnames.

ORIORDAN is an anglicized version of the original Irish Gaelic spelling, as many Irish names were adapted to English spellings during the centuries of English rule in Ireland. The earliest recorded instances of the name can be found in ancient Irish annals and manuscripts, such as the Annals of Inisfallen, which date back to the 12th and 13th centuries.

One of the earliest documented individuals with this surname was Donal O'Riordan, a prominent Irish chieftain who lived in the 14th century. He was a member of the powerful O'Riordan clan, which held significant influence in the Muskerry region of County Cork during the Middle Ages.

Another notable figure was Aodh Ó Rioghbhardáin, also known as Hugh O'Riordan, a 16th-century Irish poet and historian. He was a renowned scholar and is remembered for his contributions to the preservation of Irish literature and history.

In the 17th century, during the Irish Confederate Wars and the Cromwellian conquest of Ireland, many Irish families, including the ORIORDANs, lost their lands and were forced into exile. Some ORIORDANs fled to continental Europe, particularly Spain and France, where their name was sometimes spelled as "O'Riordan" or "O'Reardon."

In the 18th century, Edmund O'Riordan (1670-1737) was a prominent Irish Catholic priest and writer. He was a staunch defender of the Catholic faith during a time of religious persecution in Ireland and published several works on theological and historical subjects.

Another notable figure was John O'Riordan (1810-1872), an Irish-American architect who designed several notable buildings in New York City, including St. Patrick's Old Cathedral and the Old St. Patrick's Cathedral School.

Throughout history, the ORIORDAN surname has been associated with various place names in County Cork, such as Ballyoriordan, Cooloriordan, and Killoriordan, reflecting the clan's historical connections to specific regions within the county.

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

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

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'Riordan 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'Riordan 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'Riordan 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'Riordan, please contact us.

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