2000
#31,530
National surname rank
Recorded bearers 694
First available Census row
Per 100,000 0.26
Very Rare Last name
Dunnagan
An Anglicized form of the Irish surname Ó Dúnagáin, meaning "descendant of Dúnagán".
According to the 2020 US Census Bureau surname tables, roughly 740 Americans carry the last name Dunnagan. That puts it at #37,174 in the national surname ranking, appearing at a frequency of 0.22 per 100,000 people (about 1 in 463,182 residents).
This page is the full Name Census profile for the Dunnagan 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.
Bearers in the US
740
1 in 463,182
Census rank
#37,174
2020 decennial data
Per 100,000
0.2
Frequency rate
Recorded bearers
645
very rare in the US
Popularity narrative
The Census Bureau recorded 645 bearers of the surname Dunnagan in its 2020 decennial surname file. At a rate of 0.22 per 100,000 residents, it holds the 37174th position in the national surname ranking.
Among Census respondents with the surname Dunnagan, the largest self-reported group is White at 86.8%. The next largest groups are Two or More Races (6.4%) and Hispanic (2.9%).
Origin
Meaning and origin of Dunnagan
The surname Dunnagan has its origins in the Irish Gaelic language and is believed to have originated in the early medieval period. The name is a derivative of the Gaelic words "donn" meaning brown or dark, and "agan" which is a diminutive suffix. It is thought that the name may have initially referred to someone with dark or brown hair or complexion.
Dunnagan is considered an Anglicized version of the original Gaelic surname, which was likely spelled in various ways such as Ó Donnagáin or Ó Donngáin. The prefix "Ó" signifies a descendant or grandson, indicating that the name was originally a patronymic, referring to the descendants of a particular individual named Donnagán or Donngán.
Some of the earliest recorded instances of the name can be found in historical Irish annals and manuscripts dating back to the 16th and 17th centuries. For example, the Annals of the Four Masters, a chronicle of medieval Irish history, mention a Donnchadh Ó Donnagáin who was slain in 1546.
In the 17th century, the name appears in the Petty's Census of Ireland, a survey conducted in 1659, where it is recorded as "O'Donnegan" in County Fermanagh and County Cavan. This suggests that the Dunnagan family may have had its roots in these regions of Ulster.
One notable individual with the surname Dunnagan was James Dunnagan, an Irish mathematician and astronomer who lived from 1782 to 1851. He was a professor at the Royal College of St. Patrick in Maynooth and made significant contributions to the field of celestial mechanics.
Another historical figure was John Dunnagan, a soldier who fought in the American Revolutionary War. He was born in County Antrim, Ireland, in 1755 and later emigrated to Pennsylvania, where he joined the Continental Army and participated in several battles against the British.
In the 19th century, the Dunnagan name can be found in various records and publications, such as the 1861 census of Ireland, where it appears in counties like Fermanagh, Cavan, and Monaghan.
One notable bearer of the name was Margaret Dunnagan, an Irish poet and writer who lived from 1856 to 1943. She was born in County Fermanagh and is known for her works in the Irish language, as well as her advocacy for Irish cultural revival.
Another significant figure was Michael Dunnagan, an Irish-American politician who served as a member of the New York State Assembly from 1902 to 1906. He was born in County Cavan, Ireland, in 1865 and later immigrated to the United States.
Demographics
Ancestry and ethnicity for Dunnagan
Among Census respondents with the surname Dunnagan, the largest self-reported group is White at 86.8%. The next largest groups are Two or More Races (6.4%) and Hispanic (2.9%).
The bar chart below shows how Dunnagan 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 Dunnagan surname at the time of the 2020 Census, not any inherent property of the name itself.
- White86.8% · 560
- Two or more races6.4% · 41
- Hispanic or Latino2.9% · 19
- Black or African American1.9% · 12
- American Indian and Alaska Native1.4% · 9
- Asian and Pacific Islander0.6% · 4
Timeline
Historical Census data for Dunnagan
Dunnagan 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
#37,076
National surname rank
Recorded bearers 602
-92 bearers (-13.3%)
Per 100,000 0.20
Rank movement Down 5,546 places
2020
#37,174
National surname rank
Recorded bearers 645
+43 bearers (+7.1%)
Per 100,000 0.22
Rank movement Down 98 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #31,530 | 694 | 0.26 | First available Census row | First available Census row |
| 2010 | #37,076 | 602 | 0.20 | -92 bearers (-13.3%) | Down 5,546 places |
| 2020 | #37,174 | 645 | 0.22 | +43 bearers (+7.1%) | Down 98 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 Dunnagan 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 | #37,076 | #37,174 | -0.3% |
| Count | 602 | 645 | 7.1% |
| Per 100K | 0.20 | 0.22 | 7.9% |
Between the 2010 and 2020 Census, the number of Dunnagan bearers went from 602 to 645 (+7.1% change). The surname moved down 98 positions in the national ranking, going from #37,076 to #37,174.
FAQ
Dunnagan surname: questions and answers
How many people in the U.S. have the surname Dunnagan?
Name Census estimates that about 740 living Americans carry the surname Dunnagan. Using the current population baseline, that works out to roughly 1 in 463,182 residents.
How common is Dunnagan?
Dunnagan ranks #37,174 in the 2020 Census surname tables and is classified on this site as "Very Rare." The Census recorded the name at a frequency of 0.22 per 100,000 residents, which is about 0 people out of every 100,000.
How many people with this surname were counted in the Census?
The raw 2020 Census file counted 645 people with the surname Dunnagan. That is different from the site's living-bearer estimate (740), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 0.22 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 0.22 per 100,000 means that if you picked a random group of 100,000 U.S. residents, you would expect about 0 of them to have the surname Dunnagan.
Has Dunnagan become more or less common over time?
Between 2010 and 2020, the surname Dunnagan went from 602 recorded bearers to 645. That is an increase of 43 (+7.1%). In the national ranking it fell from #37,076 to #37,174.
What does the Census say about the background of Dunnagan?
Among Census respondents with the surname Dunnagan, the largest self-reported group is White at 86.8%. The next largest groups are Two or More Races (6.4%) and Hispanic (2.9%). 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 Dunnagan in the 2020 Census, accounting for 86.8% (560 people in the source table).
What is the full ancestry breakdown?
Dunnagan appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (86.8%), Two or More Races (6.4%), Hispanic (2.9%). 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 Dunnagan (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 Dunnagan mean?
An Anglicized form of the Irish surname Ó Dúnagáin, meaning "descendant of Dúnagán". 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 Dunnagan (0.22 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 many people have the surname Dunnagan?
HowManyOfMe.org, our sister site, answers that with the living-bearer count in one glance.