2000
#3,504
National surname rank
Recorded bearers 9,327
First available Census row
Per 100,000 3.46
Uncommon Last name
Mahon
An Irish surname derived from the Gaelic "Mathghamhain," meaning "bear."
According to the 2020 US Census Bureau surname tables, roughly 10,285 Americans carry the last name Mahon. That puts it at #3,852 in the national surname ranking, appearing at a frequency of 3.00 per 100,000 people (about 1 in 33,326 residents).
This page is the full Name Census profile for the Mahon surname. You will find the Census Bureau frequency data, a multi-census history view, an ancestry and ethnicity breakdown based on self-reported demographics, the name's meaning and origin where available, and answers to the most common questions people ask about this surname.
For British records, Name Census UK has a British surname profile for Mahon with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
10K
1 in 33,326
Census rank
#3,852
2020 decennial data
Per 100,000
3.0
Frequency rate
Recorded bearers
9.0K
uncommon in the US
Popularity narrative
The Census Bureau recorded 8,969 bearers of the surname Mahon in its 2020 decennial surname file. At a rate of 3.00 per 100,000 residents, it holds the 3852nd position in the national surname ranking.
Among Census respondents with the surname Mahon, the largest self-reported group is White at 87.1%. The next largest groups are Black (4.9%) and Hispanic (4.0%).
Origin
Meaning and origin of Mahon
The surname Mahon has its origins in Ireland and is derived from the Irish Gaelic name "O'Mathghamhna," meaning "descendant of Mathghamhain." The clan name Mathghamhain is believed to have originated from the Old Irish personal name "Math-ghaimhin," which means "bear-calf" or "son of the bear."
One of the earliest recorded instances of the name Mahon can be found in the Annals of the Four Masters, a chronicle of medieval Irish history, which mentions a chieftain named Mahon O'Brien who lived in the 12th century. The Mahon family was historically associated with County Cork in the province of Munster, where they held significant influence and power.
In the 16th century, the Mahon family played a prominent role during the Desmond Rebellions, a series of uprisings against English rule in Ireland. One notable figure was Sir William Mahon, who served as the Lord President of Munster and was instrumental in suppressing the rebellion led by James Fitzmaurice Fitzgerald, the cousin of the Earl of Desmond.
Another notable individual with the surname Mahon was Reverend Hugh Mahon, an Irish Catholic priest born in County Cork in 1857. He served as the President of St. Patrick's College in Maynooth and was known for his efforts in promoting Catholic education in Ireland.
The Mahon surname can also be found in various historical records, such as the Pipe Rolls of Cloyne, which date back to the 13th century and mention individuals with the name. Additionally, the name appears in the Fiants of the Tudor Sovereigns, a collection of letters patent issued by the English monarchy during the Tudor period.
Throughout history, several prominent figures have borne the surname Mahon, including:
1. Andrew Mahon (1752-1817), an Irish-American merchant and politician who served in the Pennsylvania General Assembly.
2. Lord Hartington Mahon (1805-1875), an Irish politician and writer who served as the Member of Parliament for Roscommon and later as the Secretary of State for Ireland.
3. James Mahon (1837-1891), an Irish-born Australian politician who served as a member of the Legislative Assembly of Victoria.
4. William Mahon (1849-1920), an Irish-born Australian politician and journalist who served as the Premier of Western Australia from 1901 to 1904.
5. Andrew Mahon (1882-1952), an Irish Catholic priest and writer who served as the President of St. Patrick's College in Maynooth.
While the Mahon surname has its roots in Ireland, it has since spread to various parts of the world due to Irish emigration and has become a part of the cultural fabric in countries like the United States, Australia, and others.
Demographics
Ancestry and ethnicity for Mahon
Among Census respondents with the surname Mahon, the largest self-reported group is White at 87.1%. The next largest groups are Black (4.9%) and Hispanic (4.0%).
The bar chart below shows how Mahon bearers described their own race and ethnicity on the 2020 Census form. The Census Bureau groups responses into six broad categories: White, Black or African American, Hispanic or Latino, Asian and Pacific Islander, American Indian and Alaska Native, and Two or More Races. When a category has too few respondents for a given surname, the Bureau suppresses the figure to protect individual privacy, which is why some names show fewer than six slices.
Percentages are shown for every Census year so the breakdown stays comparable over time. When the source file also includes raw headcounts, Name Census shows those alongside the percentages in the legend.
Keep in mind that these are self-reported numbers. A person's surname does not determine their race or ethnicity, and the distribution you see here reflects the specific population who happened to carry the Mahon surname at the time of the 2020 Census, not any inherent property of the name itself.
- White87.1% · 7,811
- Black or African American4.9% · 441
- Hispanic or Latino4.0% · 356
- Two or more races3.1% · 274
- Asian and Pacific Islander0.6% · 58
- American Indian and Alaska Native0.3% · 29
Timeline
Historical Census data for Mahon
Mahon appears in 3 published Census surname files: 2000, 2010, 2020. The cards below show how the name's rank and bearer count changed across each release.
2010
#3,749
National surname rank
Recorded bearers 9,441
+114 bearers (+1.2%)
Per 100,000 3.20
Rank movement Down 245 places
2020
#3,852
National surname rank
Recorded bearers 8,969
-472 bearers (-5.0%)
Per 100,000 3.00
Rank movement Down 103 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #3,504 | 9,327 | 3.46 | First available Census row | First available Census row |
| 2010 | #3,749 | 9,441 | 3.20 | +114 bearers (+1.2%) | Down 245 places |
| 2020 | #3,852 | 8,969 | 3.00 | -472 bearers (-5.0%) | Down 103 places |
For 2020, the Census Bureau published race and Hispanic-origin columns as counts rather than percentages. Name Census converts those counts back into shares so the ancestry section stays comparable with the older surname files.
Year on year
2010 vs 2020 Census
How has the Mahon surname changed between Census years? The chart shows bearer count side by side, and the table compares rank, count, and frequency.
Census year comparison
20102020
| Metric | 2010 | 2020 | Change |
|---|---|---|---|
| Rank | #3,749 | #3,852 | -2.7% |
| Count | 9,441 | 8,969 | -5.0% |
| Per 100K | 3.20 | 3.00 | -6.2% |
Between the 2010 and 2020 Census, the number of Mahon bearers went from 9,441 to 8,969 (-5.0% change). The surname moved down 103 positions in the national ranking, going from #3,749 to #3,852.
Notable bearers
Famous people with the surname Mahon
FAQ
Mahon surname: questions and answers
How many people in the U.S. have the surname Mahon?
Name Census estimates that about 10,285 living Americans carry the surname Mahon. Using the current population baseline, that works out to roughly 1 in 33,326 residents.
How common is Mahon?
Mahon ranks #3,852 in the 2020 Census surname tables and is classified on this site as "Uncommon." The Census recorded the name at a frequency of 3.00 per 100,000 residents, which is about 3 people out of every 100,000.
How many people with this surname were counted in the Census?
The raw 2020 Census file counted 8,969 people with the surname Mahon. That is different from the site's living-bearer estimate (10,285), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 3 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 3.00 per 100,000 means that if you picked a random group of 100,000 U.S. residents, you would expect about 3 of them to have the surname Mahon.
Has Mahon become more or less common over time?
Between 2010 and 2020, the surname Mahon went from 9,441 recorded bearers to 8,969. That is a decrease of 472 (-5.0%). In the national ranking it fell from #3,749 to #3,852.
What does the Census say about the background of Mahon?
Among Census respondents with the surname Mahon, the largest self-reported group is White at 87.1%. The next largest groups are Black (4.9%) and Hispanic (4.0%). These figures come from the 2020 Census Bureau surname tables, based on how respondents described their own race and ethnicity.
Which group reports this surname most often?
White is the largest self-reported group for the surname Mahon in the 2020 Census, accounting for 87.1% (7,811 people in the source table).
What is the full ancestry breakdown?
Mahon appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (87.1%), Black (4.9%), Hispanic (4.0%). For 2020, the source file also published raw headcounts for each group, which is why this page can show both percentages and counts in the ancestry section.
Is this page using the latest Census data?
Yes. This page is using the latest surname file currently loaded on Name Census, which is 2020. The historical section above also keeps any older Census surname entries we have for Mahon (2000, 2010, 2020).
Does the Census include every surname?
No. The Census Bureau only publishes surnames that appeared at least 100 times in a given decennial Census. That means very rare surnames are excluded entirely, and a surname can appear in one Census release but disappear from a later one if it falls below the reporting threshold.
Why don't the ancestry percentages always add up to exactly 100%?
There are two main reasons: rounding and suppression. The Census Bureau rounds published values, and it may suppress very small cells to protect privacy. For 2020, the Bureau also published raw group counts rather than direct percentages, so Name Census converts those counts back into shares for comparability across census years.
What does Mahon mean?
An Irish surname derived from the Gaelic "Mathghamhain," meaning "bear." The fuller origin note on this page goes into more detail.
Where does the surname data come from?
All surname statistics on Name Census are drawn from the US Census Bureau's decennial surname frequency tables. These files list every surname that appeared 100 or more times in the 2020 Census, along with a count, a per-100,000 rate, and a self-reported demographic breakdown. You can read the full explanation on our methodology page.
How does Name Census estimate living bearers?
For surnames, Name Census does not age cohorts the way it does for first names. Instead, it takes the Census Bureau's published frequency for Mahon (3.00 per 100,000) and applies that rate to the current U.S. resident population to estimate how many living Americans have the surname today.
How common is the surname Mahon?
You can see how many people have the last name Mahon on our sister site HowManyOfMe.org — same data roots, lighter UI.