2000
#591
National surname rank
Recorded bearers 51,500
First available Census row
Per 100,000 19.09
Uncommon Last name
Sweeney
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 57,761 Americans carry the last name Sweeney. That puts it at #660 in the national surname ranking, appearing at a frequency of 16.85 per 100,000 people (about 1 in 5,934 residents).
This page is the full Name Census profile for the Sweeney 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 Sweeney with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
58K
1 in 5,934
Census rank
#660
2020 decennial data
Per 100,000
16.9
Frequency rate
Recorded bearers
50K
uncommon in the US
Popularity narrative
The Census Bureau recorded 50,370 bearers of the surname Sweeney in its 2020 decennial surname file. At a rate of 16.85 per 100,000 residents, it holds the 660th position in the national surname ranking.
Among Census respondents with the surname Sweeney, the largest self-reported group is White at 87.6%. The next largest groups are Black (4.7%) and Hispanic (3.4%).
Origin
Meaning and origin of Sweeney
The surname Sweeney originated in Ireland and dates back to the 12th century. It is an anglicized form of the Gaelic name O'Suanaigh, which means "descendant of Suanach." The name Suanach itself is derived from the Gaelic word "suan," meaning "sleep" or "slumber."
Sweeney is a common surname found primarily in counties Cork, Kerry, and Limerick in the southwestern part of Ireland. The earliest recorded instances of the name can be found in the Annals of Inisfallen, a chronicle of medieval Irish history compiled at the monastery on Inisfallen Island in County Kerry.
One of the earliest recorded bearers of the name was Donnchadh O'Suanaigh, who was the Bishop of Limerick from 1207 to 1224. Another notable figure was Niall O'Suanaigh, who served as the Chief of the Name and Lord of Clonderlaw in County Clare in the 14th century.
The Sweeney family played a significant role in the wars between the Irish chieftains and the Anglo-Norman invaders in the 13th and 14th centuries. Several members of the family were noted warriors and leaders, including Dermot Sweeney, who was killed in battle against the English in 1369.
In the 16th century, the Sweeneys were among the Irish families who were dispossessed of their lands during the Plantations of Munster and Ulster. Some Sweeneys anglicized their name to Swayne or Swain to avoid persecution.
Notable individuals with the surname Sweeney include John Sweeney (1766-1839), an Irish-American author and journalist; Jane Sweeney (1815-1891), an Irish-American labor activist and advocate for women's rights; and John Cameron Sweeney (1900-1986), an American poet and literary critic.
Other famous Sweeneys include Francis Sweeney (1811-1890), an Irish-American Catholic priest and founder of the Sisters of Mercy in San Francisco, and John Sweeney (born 1934), an American labor leader who served as the president of the AFL-CIO from 1995 to 2009.
Demographics
Ancestry and ethnicity for Sweeney
Among Census respondents with the surname Sweeney, the largest self-reported group is White at 87.6%. The next largest groups are Black (4.7%) and Hispanic (3.4%).
The bar chart below shows how Sweeney 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 Sweeney surname at the time of the 2020 Census, not any inherent property of the name itself.
- White87.6% · 44,143
- Black or African American4.7% · 2,386
- Hispanic or Latino3.4% · 1,702
- Two or more races3.1% · 1,583
- Asian and Pacific Islander0.7% · 375
- American Indian and Alaska Native0.4% · 181
Timeline
Historical Census data for Sweeney
Sweeney 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
#651
National surname rank
Recorded bearers 52,410
+910 bearers (+1.8%)
Per 100,000 17.77
Rank movement Down 60 places
2020
#660
National surname rank
Recorded bearers 50,370
-2,040 bearers (-3.9%)
Per 100,000 16.85
Rank movement Down 9 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #591 | 51,500 | 19.09 | First available Census row | First available Census row |
| 2010 | #651 | 52,410 | 17.77 | +910 bearers (+1.8%) | Down 60 places |
| 2020 | #660 | 50,370 | 16.85 | -2,040 bearers (-3.9%) | Down 9 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 Sweeney 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 | #651 | #660 | -1.4% |
| Count | 52,410 | 50,370 | -3.9% |
| Per 100K | 17.77 | 16.85 | -5.2% |
Between the 2010 and 2020 Census, the number of Sweeney bearers went from 52,410 to 50,370 (-3.9% change). The surname moved down 9 positions in the national ranking, going from #651 to #660.
Notable bearers
Famous people with the surname Sweeney
FAQ
Sweeney surname: questions and answers
How many people in the U.S. have the surname Sweeney?
Name Census estimates that about 57,761 living Americans carry the surname Sweeney. Using the current population baseline, that works out to roughly 1 in 5,934 residents.
How common is Sweeney?
Sweeney ranks #660 in the 2020 Census surname tables and is classified on this site as "Uncommon." The Census recorded the name at a frequency of 16.85 per 100,000 residents, which is about 17 people out of every 100,000.
How many people with this surname were counted in the Census?
The raw 2020 Census file counted 50,370 people with the surname Sweeney. That is different from the site's living-bearer estimate (57,761), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 16.85 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 16.85 per 100,000 means that if you picked a random group of 100,000 U.S. residents, you would expect about 17 of them to have the surname Sweeney.
Has Sweeney become more or less common over time?
Between 2010 and 2020, the surname Sweeney went from 52,410 recorded bearers to 50,370. That is a decrease of 2,040 (-3.9%). In the national ranking it fell from #651 to #660.
What does the Census say about the background of Sweeney?
Among Census respondents with the surname Sweeney, the largest self-reported group is White at 87.6%. The next largest groups are Black (4.7%) and Hispanic (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 Sweeney in the 2020 Census, accounting for 87.6% (44,143 people in the source table).
What is the full ancestry breakdown?
Sweeney appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (87.6%), Black (4.7%), Hispanic (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 Sweeney (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 Sweeney 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 Sweeney (16.85 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 Sweeney?
For a faster, more casual read, check HowManyOfMe.org — our sister site built around that single question.