2000
#22,403
National surname rank
Recorded bearers 1,072
First available Census row
Per 100,000 0.40
Rare Last name
Fennelly
An Irish surname derived from the Gaelic surname Ó Fionnalaidh, meaning "descendant of a fair-haired one."
According to the 2020 US Census Bureau surname tables, roughly 1,243 Americans carry the last name Fennelly. That puts it at #24,083 in the national surname ranking, appearing at a frequency of 0.36 per 100,000 people (about 1 in 275,748 residents).
This page is the full Name Census profile for the Fennelly 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 Fennelly with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
1.2K
1 in 275,748
Census rank
#24,083
2020 decennial data
Per 100,000
0.4
Frequency rate
Recorded bearers
1.1K
rare in the US
Popularity narrative
The Census Bureau recorded 1,084 bearers of the surname Fennelly in its 2020 decennial surname file. At a rate of 0.36 per 100,000 residents, it holds the 24083rd position in the national surname ranking.
Among Census respondents with the surname Fennelly, the largest self-reported group is White at 91.5%. The next largest groups are Hispanic (3.5%) and Two or More Races (3.4%).
Origin
Meaning and origin of Fennelly
The surname Fennelly originated in Ireland and has its roots in the Irish Gaelic language. It is a variant of the name Fennessy, which is derived from the old Irish personal name "Fionnghus," meaning "fair-haired." This name was brought to Ireland by Viking settlers during the 9th and 10th centuries.
The name Fennelly is most commonly found in County Cork and County Kerry in the southwestern part of Ireland. It is believed that the earliest recorded instances of the name date back to the 13th century, though it is difficult to pinpoint the exact origin due to the lack of comprehensive historical records from that time.
One of the earliest known references to the name Fennelly can be found in the "Annals of the Four Masters," a chronicle of medieval Irish history compiled in the early 17th century. This text mentions a "Fennessy" family as landowners in County Cork during the 14th century.
In the 16th century, the Fennelly name appears in the "Fiants of the Tudor Sovereigns," a collection of documents relating to the administration of Ireland during the Tudor period. These records list several individuals with the surname Fennelly as holders of land grants and other official positions.
Notable individuals with the surname Fennelly throughout history include:
1. Maurice Fennelly (c. 1600 - 1680), an Irish military leader who fought in the Confederate Wars of the 1640s.
2. Jeremiah Fennelly (1766 - 1842), an Irish-American soldier who served in the American Revolutionary War.
3. Richard Fennelly (1823 - 1893), an Irish-born Australian politician and member of the New South Wales Legislative Assembly.
4. Mary Fennelly (1892 - 1969), an Irish-American labor organizer and activist for workers' rights.
5. Daniel Fennelly (1939 - 2010), an American author and playwright known for his works depicting Irish-American culture.
While the surname Fennelly has roots in Ireland, it has since spread to other parts of the world, particularly through Irish emigration to countries like the United States, Australia, and the United Kingdom.
Demographics
Ancestry and ethnicity for Fennelly
Among Census respondents with the surname Fennelly, the largest self-reported group is White at 91.5%. The next largest groups are Hispanic (3.5%) and Two or More Races (3.4%).
The bar chart below shows how Fennelly 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 Fennelly surname at the time of the 2020 Census, not any inherent property of the name itself.
- White91.5% · 992
- Hispanic or Latino3.5% · 38
- Two or more races3.4% · 37
- Asian and Pacific Islander0.8% · 9
- Black or African American0.7% · 8
Timeline
Historical Census data for Fennelly
Fennelly 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
#31,790
National surname rank
Recorded bearers 726
-346 bearers (-32.3%)
Per 100,000 0.25
Rank movement Down 9,387 places
2020
#24,083
National surname rank
Recorded bearers 1,084
+358 bearers (+49.3%)
Per 100,000 0.36
Rank movement Up 7,707 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #22,403 | 1,072 | 0.40 | First available Census row | First available Census row |
| 2010 | #31,790 | 726 | 0.25 | -346 bearers (-32.3%) | Down 9,387 places |
| 2020 | #24,083 | 1,084 | 0.36 | +358 bearers (+49.3%) | Up 7,707 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 Fennelly 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 | #31,790 | #24,083 | 24.2% |
| Count | 726 | 1,084 | 49.3% |
| Per 100K | 0.25 | 0.36 | 45.1% |
Between the 2010 and 2020 Census, the number of Fennelly bearers went from 726 to 1,084 (+49.3% change). The surname moved up 7,707 positions in the national ranking, going from #31,790 to #24,083.
FAQ
Fennelly surname: questions and answers
How many people in the U.S. have the surname Fennelly?
Name Census estimates that about 1,243 living Americans carry the surname Fennelly. Using the current population baseline, that works out to roughly 1 in 275,748 residents.
How common is Fennelly?
Fennelly ranks #24,083 in the 2020 Census surname tables and is classified on this site as "Rare." The Census recorded the name at a frequency of 0.36 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 1,084 people with the surname Fennelly. That is different from the site's living-bearer estimate (1,243), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 0.36 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 0.36 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 Fennelly.
Has Fennelly become more or less common over time?
Between 2010 and 2020, the surname Fennelly went from 726 recorded bearers to 1,084. That is an increase of 358 (+49.3%). In the national ranking it rose from #31,790 to #24,083.
What does the Census say about the background of Fennelly?
Among Census respondents with the surname Fennelly, the largest self-reported group is White at 91.5%. The next largest groups are Hispanic (3.5%) and Two or More Races (3.4%). 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 Fennelly in the 2020 Census, accounting for 91.5% (992 people in the source table).
What is the full ancestry breakdown?
Fennelly appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (91.5%), Hispanic (3.5%), Two or More Races (3.4%). 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 Fennelly (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 Fennelly mean?
An Irish surname derived from the Gaelic surname Ó Fionnalaidh, meaning "descendant of a fair-haired one." 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 Fennelly (0.36 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 are called Fennelly?
You can see how many people have the last name Fennelly on our sister site HowManyOfMe.org — same data roots, lighter UI.