2000
#114,166
National surname rank
Recorded bearers 142
First available Census row
Per 100,000 0.05
Very Rare Last name
Denneny
From an Irish surname meaning brave or courageous.
According to the 2020 US Census Bureau surname tables, roughly 122 Americans carry the last name Denneny. That puts it at #152,339 in the national surname ranking, appearing at a frequency of 0.04 per 100,000 people (about 1 in 2,809,462 residents).
This page is the full Name Census profile for the Denneny 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
122
1 in 2,809,462
Census rank
#152,339
2020 decennial data
Per 100,000
0.0
Frequency rate
Recorded bearers
106
very rare in the US
Popularity narrative
The Census Bureau recorded 106 bearers of the surname Denneny in its 2020 decennial surname file. At a rate of 0.04 per 100,000 residents, it holds the 152339th position in the national surname ranking.
Among Census respondents with the surname Denneny, the largest self-reported group is White at 91.5%. The next largest groups are Two or More Races (6.6%) and Hispanic (1.9%).
Origin
Meaning and origin of Denneny
The surname Denneny has its origins in Ireland, dating back to the 16th century. It is believed to be a variant of the Irish surname Denahy or Dineen, which were anglicized spellings of the Gaelic name "O'Donnchadha" or "O'Donnchadha". This name is derived from the Irish personal name "Donnchadh", meaning "brown warrior" or "brown battle."
The earliest recorded instances of the name Denneny can be found in various Irish records and manuscripts from the 16th and 17th centuries. One notable example is the Fiants of the Tudor Sovereigns, a collection of administrative records from the reigns of Henry VIII, Edward VI, Mary I, and Elizabeth I, which mentions individuals with the surname Denneny or its variants.
In the 18th century, the Denneny surname was concentrated in County Cork and County Kerry, particularly in the areas around Dingle and the Iveragh Peninsula. Some of the earliest recorded individuals with this surname include John Denneny, born in 1712 in Dingle, and Patrick Denneny, born in 1745 in Cahersiveen, County Kerry.
Throughout the 19th century, the Denneny surname began to spread beyond its traditional strongholds in Munster due to migration and emigration. Notable individuals from this period include Michael Denneny (1812-1891), a prominent Irish nationalist and member of the Young Irelanders movement, and John Denneny (1828-1902), a successful businessman and philanthropist from County Kerry.
In the early 20th century, the Denneny surname continued to be found primarily in Ireland, with some individuals emigrating to other parts of the world, such as the United States and Australia. One notable individual from this period was James Denneny (1876-1954), a Irish-born businessman and politician who served as a member of the Australian House of Representatives.
Other notable individuals with the surname Denneny throughout history include Robert Denneny (1864-1940), an Irish-born American architect who designed several notable buildings in New York City, and Seán Denneny (1912-1987), an Irish Gaelic football player and manager who played for and managed the Kerry senior football team.
Demographics
Ancestry and ethnicity for Denneny
Among Census respondents with the surname Denneny, the largest self-reported group is White at 91.5%. The next largest groups are Two or More Races (6.6%) and Hispanic (1.9%).
The bar chart below shows how Denneny 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 Denneny surname at the time of the 2020 Census, not any inherent property of the name itself.
- White91.5% · 97
- Two or more races6.6% · 7
- Hispanic or Latino1.9% · 2
Timeline
Historical Census data for Denneny
Denneny 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
#129,047
National surname rank
Recorded bearers 132
-10 bearers (-7.0%)
Per 100,000 0.04
Rank movement Down 14,881 places
2020
#152,339
National surname rank
Recorded bearers 106
-26 bearers (-19.7%)
Per 100,000 0.04
Rank movement Down 23,292 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #114,166 | 142 | 0.05 | First available Census row | First available Census row |
| 2010 | #129,047 | 132 | 0.04 | -10 bearers (-7.0%) | Down 14,881 places |
| 2020 | #152,339 | 106 | 0.04 | -26 bearers (-19.7%) | Down 23,292 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 Denneny 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 | #129,047 | #152,339 | -18.0% |
| Count | 132 | 106 | -19.7% |
| Per 100K | 0.04 | 0.04 | -11.3% |
Between the 2010 and 2020 Census, the number of Denneny bearers went from 132 to 106 (-19.7% change). The surname moved down 23,292 positions in the national ranking, going from #129,047 to #152,339.
FAQ
Denneny surname: questions and answers
How many people in the U.S. have the surname Denneny?
Name Census estimates that about 122 living Americans carry the surname Denneny. Using the current population baseline, that works out to roughly 1 in 2,809,462 residents.
How common is Denneny?
Denneny ranks #152,339 in the 2020 Census surname tables and is classified on this site as "Very Rare." The Census recorded the name at a frequency of 0.04 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 106 people with the surname Denneny. That is different from the site's living-bearer estimate (122), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 0.04 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 0.04 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 Denneny.
Has Denneny become more or less common over time?
Between 2010 and 2020, the surname Denneny went from 132 recorded bearers to 106. That is a decrease of 26 (-19.7%). In the national ranking it fell from #129,047 to #152,339.
What does the Census say about the background of Denneny?
Among Census respondents with the surname Denneny, the largest self-reported group is White at 91.5%. The next largest groups are Two or More Races (6.6%) and Hispanic (1.9%). 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 Denneny in the 2020 Census, accounting for 91.5% (97 people in the source table).
What is the full ancestry breakdown?
Denneny appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (91.5%), Two or More Races (6.6%), Hispanic (1.9%). 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 Denneny (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 Denneny mean?
From an Irish surname meaning brave or courageous. 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 Denneny (0.04 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 Denneny?
If you just want to know how many people are called Denneny, HowManyOfMe.org gives you the headline number in one glance.