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

Hennessey, 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 Hennessey surname is from the 2010 census data.

Popularity of Hennessey in America

Hennessey is the 4245th most popular name in America based on the data we have collected from the U.S. Census Bureau.

The Hennessey surname appeared 8,357 times in the 2010 census and if you were to sample 100,000 people in the United States, approximately 3 people would have the surname Hennessey.

We can also compare 2010 data for Hennessey 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 Hennessey

The surname Hennessey originates from Ireland, where it emerged in the 16th century. It is an Anglicized form of the Irish Gaelic surname Ó hAonghusa, derived from the personal name Aonghus, meaning "one choice" or "one strength."

This name is believed to have originated in County Cork, where the Ó hAonghusa clan was based. The earliest recorded instances of the name appear in the Annals of the Four Masters, a chronicle of medieval Irish history compiled in the 17th century.

One notable early bearer of the name was Rory Hennessey, a 16th-century Irish chieftain who fought against English forces during the Tudor conquest of Ireland. Another historical figure was Bartholomew Hennessey, a 17th-century Catholic priest who was executed during the Cromwellian conquest of Ireland.

In the 18th century, the name Hennessey gained prominence with the success of the Hennessy Cognac brand, founded by Richard Hennessy, an Irish officer in the French army. The brand's popularity helped to spread the name throughout Europe and beyond.

Other notable individuals with the surname Hennessey include:

1. John Hennessey (1834-1912), an Irish-American entrepreneur and founder of the Hennessey & Ingalls advertising agency in Los Angeles.
2. John Francis Hennessey (1866-1939), an American politician who served as Governor of New Hampshire from 1917 to 1919.
3. Thomas Hennessey (1906-1979), an Australian rules footballer who played for the Carlton Football Club in the 1920s and 1930s.
4. Neil Hennessy (born 1952), an Irish-American businessman and founder of the Hennessy Funds investment firm.
5. John Hennessey (born 1964), an American automotive engineer and founder of Hennessey Performance Engineering, a company specializing in modifying high-performance vehicles.

The surname Hennessey has undergone various spelling variations over the centuries, including Hennessy, Henesey, and Hennesy. Some of these variations reflect regional pronunciations or attempts to Anglicize the name further.

Race and ethnic origin of people with the last name Hennessey

We also have some data on the ancestry of people with the surname Hennessey.

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 Hennessey 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 Hennessey 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 Hennessey was researched and written by our team of onomatology and genealogy experts.

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

Reference this page

We spend a lot of resources downloading, cleaning, merging, and formatting the data that is shown on the site.

If you found the data or information on this page useful in your research, please use the tool below to properly cite or reference Name Census as the source. We appreciate your support!