2000
#7,811
National surname rank
Recorded bearers 3,927
First available Census row
Per 100,000 1.46
Rare Last name
Drennan
An Irish toponymic surname derived from the Gaelic Ó Draighnáin, meaning "descendant of Draighnán" (a diminutive of "blackthorn").
According to the 2020 US Census Bureau surname tables, roughly 4,634 Americans carry the last name Drennan. That puts it at #7,876 in the national surname ranking, appearing at a frequency of 1.35 per 100,000 people (about 1 in 73,965 residents).
This page is the full Name Census profile for the Drennan 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 Drennan with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
4.6K
1 in 73,965
Census rank
#7,876
2020 decennial data
Per 100,000
1.4
Frequency rate
Recorded bearers
4.0K
rare in the US
Popularity narrative
The Census Bureau recorded 4,041 bearers of the surname Drennan in its 2020 decennial surname file. At a rate of 1.35 per 100,000 residents, it holds the 7876th position in the national surname ranking.
Among Census respondents with the surname Drennan, the largest self-reported group is White at 89.7%. The next largest groups are Hispanic (4.0%) and Two or More Races (2.8%).
Origin
Meaning and origin of Drennan
The surname Drennan is of Irish origin, derived from the Gaelic name "O'Drennain" which means "descendant of Drennan". It is believed to have originated in the ancient Dalriada region of Scotland, which encompasses parts of modern-day Argyll and Antrim.
The earliest recorded instances of the name can be traced back to the 12th century in County Antrim, Ireland. One of the earliest documented references is in the Annals of the Four Masters, which mentions a chieftain named Niall O'Drennan in 1171.
During the medieval period, the Drennan surname was prominent in the Glens of Antrim, particularly in the areas of Glenarm and Cushendall. The name is also associated with several place names in the region, such as Drennanstown and Drennans Mill.
In the 16th century, the Drennan family played a significant role in the Irish Confederate Wars, with several members serving as officers in the Confederate Catholic forces. One notable figure was Conn O'Drennan, who led a contingent of soldiers from Antrim in the Battle of Benburbh in 1646.
During the Plantation of Ulster in the 17th century, many Drennan families were displaced from their ancestral lands and migrated to other parts of Ireland, as well as to the Americas and other British colonies. This led to the widespread distribution of the surname across various regions.
Notable individuals with the Drennan surname include:
1. William Drennan (1754-1820), an Irish physician, poet, and political radical, who co-founded the Society of United Irishmen.
2. John Drennan (1791-1866), an Irish-American merchant and philanthropist, who established the Drennan Institute in Charleston, South Carolina.
3. Ann Drennan (1809-1892), an Irish botanist and author, known for her work on algae and lichens.
4. Thomas Drennan (1809-1892), an Irish-Canadian politician and businessman, who served as a member of the Legislative Assembly of the Province of Canada.
5. Mathew Drennan (1826-1904), an Irish-American entrepreneur and industrialist, who founded the Drennan Axe and Tool Company in New York.
The Drennan surname has a rich history rooted in the ancient Gaelic traditions of Ireland and Scotland. Its prevalence throughout the centuries and its association with various historical figures and events make it a significant part of the cultural heritage of the British Isles and beyond.
Demographics
Ancestry and ethnicity for Drennan
Among Census respondents with the surname Drennan, the largest self-reported group is White at 89.7%. The next largest groups are Hispanic (4.0%) and Two or More Races (2.8%).
The bar chart below shows how Drennan 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 Drennan surname at the time of the 2020 Census, not any inherent property of the name itself.
- White89.7% · 3,624
- Hispanic or Latino4.0% · 163
- Two or more races2.8% · 114
- American Indian and Alaska Native2.0% · 80
- Black or African American0.9% · 36
- Asian and Pacific Islander0.6% · 24
Timeline
Historical Census data for Drennan
Drennan 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
#7,821
National surname rank
Recorded bearers 4,233
+306 bearers (+7.8%)
Per 100,000 1.44
Rank movement Down 10 places
2020
#7,876
National surname rank
Recorded bearers 4,041
-192 bearers (-4.5%)
Per 100,000 1.35
Rank movement Down 55 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #7,811 | 3,927 | 1.46 | First available Census row | First available Census row |
| 2010 | #7,821 | 4,233 | 1.44 | +306 bearers (+7.8%) | Down 10 places |
| 2020 | #7,876 | 4,041 | 1.35 | -192 bearers (-4.5%) | Down 55 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 Drennan 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 | #7,821 | #7,876 | -0.7% |
| Count | 4,233 | 4,041 | -4.5% |
| Per 100K | 1.44 | 1.35 | -6.1% |
Between the 2010 and 2020 Census, the number of Drennan bearers went from 4,233 to 4,041 (-4.5% change). The surname moved down 55 positions in the national ranking, going from #7,821 to #7,876.
FAQ
Drennan surname: questions and answers
How many people in the U.S. have the surname Drennan?
Name Census estimates that about 4,634 living Americans carry the surname Drennan. Using the current population baseline, that works out to roughly 1 in 73,965 residents.
How common is Drennan?
Drennan ranks #7,876 in the 2020 Census surname tables and is classified on this site as "Rare." The Census recorded the name at a frequency of 1.35 per 100,000 residents, which is about 1 people out of every 100,000.
How many people with this surname were counted in the Census?
The raw 2020 Census file counted 4,041 people with the surname Drennan. That is different from the site's living-bearer estimate (4,634), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 1.35 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 1.35 per 100,000 means that if you picked a random group of 100,000 U.S. residents, you would expect about 1 of them to have the surname Drennan.
Has Drennan become more or less common over time?
Between 2010 and 2020, the surname Drennan went from 4,233 recorded bearers to 4,041. That is a decrease of 192 (-4.5%). In the national ranking it fell from #7,821 to #7,876.
What does the Census say about the background of Drennan?
Among Census respondents with the surname Drennan, the largest self-reported group is White at 89.7%. The next largest groups are Hispanic (4.0%) and Two or More Races (2.8%). 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 Drennan in the 2020 Census, accounting for 89.7% (3,624 people in the source table).
What is the full ancestry breakdown?
Drennan appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (89.7%), Hispanic (4.0%), Two or More Races (2.8%). 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 Drennan (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 Drennan mean?
An Irish toponymic surname derived from the Gaelic Ó Draighnáin, meaning "descendant of Draighnán" (a diminutive of "blackthorn"). 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 Drennan (1.35 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 Americans have the surname Drennan?
For a faster, more casual read, check HowManyOfMe.org — our sister site built around that single question.