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

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

Popularity of O'Mahoney in America

O'Mahoney is the 43584th most popular name in America based on the data we have collected from the U.S. Census Bureau.

The O'Mahoney surname appeared 495 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'Mahoney.

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

The surname OMAHONEY is an anglicized version of the Irish Gaelic name Ó Mathúna, which originated in County Cork, Ireland. The name derives from the word "mathún," meaning a bear cub or small bear, and was likely originally a nickname for someone who was considered brave or fierce.

This surname can be traced back to the 11th century, with records indicating that the Ó Mathúna clan was one of the principal families of the Uí Eachach Mumhan, a powerful dynasty that ruled over parts of Munster. The name appears in various early manuscripts, including the Annals of Inisfallen and the Book of Munster.

One of the earliest recorded individuals with this surname was Diarmaid Ó Mathúna, who served as the Chief of the Name in the 13th century. Another notable bearer of the name was Domhnall Ó Mathúna, a renowned poet and scholar who lived in the 15th century and was celebrated for his works in both Irish and Latin.

In the 16th century, the Ó Mathúna clan held lands around the town of Ballymahon (derived from Baile Uí Mhathúna, meaning "townland of the Ó Mathúnas") in County Cork. During this period, the name was also anglicized to various spellings, such as O'Mahoney, O'Mahony, and OMAHONEY.

Throughout history, several notable figures have borne this surname. Conor O'Mahony (1615-1678) was a Catholic priest who played a significant role in the Irish Confederate Wars. Theobald O'Mahony (1800-1892) was an Irish-Australian explorer and surveyor, known for his contribution to mapping the interior of Western Australia.

John Francis O'Mahony (1816-1877) was an Irish Fenian leader and journalist who founded the Fenian Brotherhood, a revolutionary organization dedicated to the establishment of an independent Irish republic. Daniel O'Mahony (1828-1892) was a prominent Irish-Australian politician and journalist who served as a member of the New South Wales Legislative Council.

Another notable bearer of the name was John O'Mahony (1875-1957), an Irish republican and member of the Irish Republican Brotherhood, who participated in the Easter Rising of 1916 and later served as a Sinn Féin member of the Parliament of Northern Ireland.

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

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

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'Mahoney 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'Mahoney 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'Mahoney 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'Mahoney, please contact us.

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