2000
#11,737
National surname rank
Recorded bearers 2,444
First available Census row
Per 100,000 0.91
Rare Last name
Sweeny
Anglicized form of the Irish surname "Mac Suibhne," meaning "son of Suibhne" (pleasant or well-disposed).
According to the 2020 US Census Bureau surname tables, roughly 2,369 Americans carry the last name Sweeny. That puts it at #13,977 in the national surname ranking, appearing at a frequency of 0.69 per 100,000 people (about 1 in 144,683 residents).
This page is the full Name Census profile for the Sweeny 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 Sweeny with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
2.4K
1 in 144,683
Census rank
#13,977
2020 decennial data
Per 100,000
0.7
Frequency rate
Recorded bearers
2.1K
rare in the US
Popularity narrative
The Census Bureau recorded 2,066 bearers of the surname Sweeny in its 2020 decennial surname file. At a rate of 0.69 per 100,000 residents, it holds the 13977th position in the national surname ranking.
Among Census respondents with the surname Sweeny, the largest self-reported group is White at 86.9%. The next largest groups are Black (4.9%) and Two or More Races (3.7%).
Origin
Meaning and origin of Sweeny
The surname Sweeny is an anglicized version of the Irish Gaelic name "Ó Suanaigh" or "O'Sweeney". It originated in County Donegal, Ireland, and can be traced back to the 10th century. The name is derived from the Gaelic word "suanach", meaning "peaceable" or "tranquil".
Historically, the Sweeneys were a prominent family in the Donegal region, holding lands and wielding significant influence. One of the earliest recorded references to the name can be found in the Annals of Ulster, a medieval chronicle that mentions the death of Maolmuire O'Sweeny, a chieftain of the O'Sweeny clan, in 1199.
The Sweeneys played a notable role in the Gaelic resistance against English colonization in the 16th and 17th centuries. Niall Garbh O'Sweeny (c.1587-1623), a renowned military leader, led his clan in several battles against the English forces. His exploits are chronicled in the Irish manuscript "Beatha Aodha Ruaidh Uí Dhomhnaill" (The Life of Red Hugh O'Donnell).
In the 17th century, another prominent figure, Turlough O'Sweeny (c.1600-1648), was a Catholic priest and historian who wrote the "Descripton of the County of Donegal". This work provides valuable insights into the history and culture of the region during that period.
The name Sweeny has also been associated with various place names in Ireland, such as Sweeny's Cross in County Donegal, which derives its name from the Sweeny clan's influence in the area.
Other notable individuals with the Sweeny surname include:
1. John Sweeny (1821-1899), an Irish-American politician and businessman who served as the first Catholic mayor of St. Louis, Missouri.
2. Robert Sweeny (1853-1909), an American baseball player and manager, considered one of the pioneers of the game.
3. Joseph Sweeny (1904-1968), an American labor leader and president of the International Brotherhood of Teamsters from 1952 to 1957.
4. Anne Sweeny (1919-2005), an American author and screenwriter known for her work on the television series "The Waltons".
5. Stephen Sweeny (1966-present), an Irish actor and director known for his roles in films such as "Michael Collins" and "The Commitments".
While the Sweeny surname has evolved over time and spread across various regions, its roots can be traced back to the historic Gaelic clan in County Donegal, Ireland, where it has left an indelible mark on the region's cultural and historical landscape.
Demographics
Ancestry and ethnicity for Sweeny
Among Census respondents with the surname Sweeny, the largest self-reported group is White at 86.9%. The next largest groups are Black (4.9%) and Two or More Races (3.7%).
The bar chart below shows how Sweeny 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 Sweeny surname at the time of the 2020 Census, not any inherent property of the name itself.
- White86.9% · 1,796
- Black or African American4.9% · 102
- Two or more races3.7% · 76
- Hispanic or Latino3.5% · 72
- Asian and Pacific Islander0.6% · 12
- American Indian and Alaska Native0.4% · 8
Timeline
Historical Census data for Sweeny
Sweeny 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
#12,362
National surname rank
Recorded bearers 2,515
+71 bearers (+2.9%)
Per 100,000 0.85
Rank movement Down 625 places
2020
#13,977
National surname rank
Recorded bearers 2,066
-449 bearers (-17.9%)
Per 100,000 0.69
Rank movement Down 1,615 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #11,737 | 2,444 | 0.91 | First available Census row | First available Census row |
| 2010 | #12,362 | 2,515 | 0.85 | +71 bearers (+2.9%) | Down 625 places |
| 2020 | #13,977 | 2,066 | 0.69 | -449 bearers (-17.9%) | Down 1,615 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 Sweeny 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 | #12,362 | #13,977 | -13.1% |
| Count | 2,515 | 2,066 | -17.9% |
| Per 100K | 0.85 | 0.69 | -18.7% |
Between the 2010 and 2020 Census, the number of Sweeny bearers went from 2,515 to 2,066 (-17.9% change). The surname moved down 1,615 positions in the national ranking, going from #12,362 to #13,977.
FAQ
Sweeny surname: questions and answers
How many people in the U.S. have the surname Sweeny?
Name Census estimates that about 2,369 living Americans carry the surname Sweeny. Using the current population baseline, that works out to roughly 1 in 144,683 residents.
How common is Sweeny?
Sweeny ranks #13,977 in the 2020 Census surname tables and is classified on this site as "Rare." The Census recorded the name at a frequency of 0.69 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 2,066 people with the surname Sweeny. That is different from the site's living-bearer estimate (2,369), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 0.69 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 0.69 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 Sweeny.
Has Sweeny become more or less common over time?
Between 2010 and 2020, the surname Sweeny went from 2,515 recorded bearers to 2,066. That is a decrease of 449 (-17.9%). In the national ranking it fell from #12,362 to #13,977.
What does the Census say about the background of Sweeny?
Among Census respondents with the surname Sweeny, the largest self-reported group is White at 86.9%. The next largest groups are Black (4.9%) and Two or More Races (3.7%). 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 Sweeny in the 2020 Census, accounting for 86.9% (1,796 people in the source table).
What is the full ancestry breakdown?
Sweeny appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (86.9%), Black (4.9%), Two or More Races (3.7%). 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 Sweeny (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 Sweeny mean?
Anglicized form of the Irish surname "Mac Suibhne," meaning "son of Suibhne" (pleasant or well-disposed). 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 Sweeny (0.69 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 Sweeny?
For a quick modern take, check how many people are called Sweeny on our sister site HowManyOfMe.org.