2000
#5,798
National surname rank
Recorded bearers 5,463
First available Census row
Per 100,000 2.03
Rare Last name
Kiley
An Anglicized form of the Irish surname Ó Caoile, meaning "descendant of Caol" (a personal name meaning "slender").
According to the 2020 US Census Bureau surname tables, roughly 6,371 Americans carry the last name Kiley. That puts it at #5,966 in the national surname ranking, appearing at a frequency of 1.86 per 100,000 people (about 1 in 53,799 residents).
This page is the full Name Census profile for the Kiley 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 Kiley with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
6.4K
1 in 53,799
Census rank
#5,966
2020 decennial data
Per 100,000
1.9
Frequency rate
Recorded bearers
5.6K
rare in the US
Popularity narrative
The Census Bureau recorded 5,556 bearers of the surname Kiley in its 2020 decennial surname file. At a rate of 1.86 per 100,000 residents, it holds the 5966th position in the national surname ranking.
Among Census respondents with the surname Kiley, the largest self-reported group is White at 91.5%. The next largest groups are Hispanic (3.1%) and Black (2.2%).
Origin
Meaning and origin of Kiley
The surname Kiley originates from Ireland and is derived from the Irish Gaelic name "O'Ceallaigh" or "Ua Ceallaigh", meaning "descendant of Ceallach". Ceallach was a personal name derived from the Irish word "ceall", meaning "church" or "monastery". The surname is believed to have emerged in the 10th or 11th century in County Offaly, Ireland.
The Kiley surname was first recorded in the Annals of the Four Masters in the 13th century, which was a chronicle of medieval Irish history. The annals mention several members of the Ua Ceallaigh family, including Maolruanaidh Ua Ceallaigh, who died in 1031, and Donnchadh Ua Ceallaigh, who was the Bishop of Clonmacnoise in 1201.
In the Domesday Book of 1086, a survey of landowners in England commissioned by William the Conqueror, there is no record of the surname Kiley. This suggests that the name had not yet spread to England at that time.
One of the earliest recorded instances of the surname Kiley is in the Irish Annals of Loch Cé, which mentions a Murchadh Ua Ceallaigh who was killed in 1188. Another early reference is in the Annals of Ulster, which mention a Domhnall Ua Ceallaigh who was the King of Uí Maine in 1227.
In the 16th century, the spelling of the surname began to evolve into more modern forms, including Kiely, Keely, and Kiley. One notable individual from this period was Sir John Keely, who was the Lord Chief Justice of Ireland from 1554 to 1556.
Other notable individuals with the surname Kiley throughout history include:
1. Thomas Kiley (1828-1907), an American politician who served as the 37th Mayor of Boston from 1888 to 1890.
2. James Kiley (1887-1952), an Irish-American actor and playwright who appeared in numerous Broadway productions and films.
3. Brendan Kiely (born 1976), an American author known for his young adult novels, including "The Last True Poets of the Sea" and "All American Boys".
4. John Kiley (1901-1983), an American football player and coach who played for the Chicago Bears and later coached at the University of Notre Dame.
5. William Kiley (1919-1994), an American architect and urban planner who designed several prominent public spaces in cities across the United States, including the East Miami Plaza in Miami, Florida.
Demographics
Ancestry and ethnicity for Kiley
Among Census respondents with the surname Kiley, the largest self-reported group is White at 91.5%. The next largest groups are Hispanic (3.1%) and Black (2.2%).
The bar chart below shows how Kiley 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 Kiley surname at the time of the 2020 Census, not any inherent property of the name itself.
- White91.5% · 5,085
- Hispanic or Latino3.1% · 171
- Black or African American2.2% · 125
- Two or more races2.0% · 110
- Asian and Pacific Islander1.1% · 59
- American Indian and Alaska Native0.1% · 6
Timeline
Historical Census data for Kiley
Kiley 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
#5,255
National surname rank
Recorded bearers 6,639
+1,176 bearers (+21.5%)
Per 100,000 2.25
Rank movement Up 543 places
2020
#5,966
National surname rank
Recorded bearers 5,556
-1,083 bearers (-16.3%)
Per 100,000 1.86
Rank movement Down 711 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #5,798 | 5,463 | 2.03 | First available Census row | First available Census row |
| 2010 | #5,255 | 6,639 | 2.25 | +1,176 bearers (+21.5%) | Up 543 places |
| 2020 | #5,966 | 5,556 | 1.86 | -1,083 bearers (-16.3%) | Down 711 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 Kiley 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 | #5,255 | #5,966 | -13.5% |
| Count | 6,639 | 5,556 | -16.3% |
| Per 100K | 2.25 | 1.86 | -17.4% |
Between the 2010 and 2020 Census, the number of Kiley bearers went from 6,639 to 5,556 (-16.3% change). The surname moved down 711 positions in the national ranking, going from #5,255 to #5,966.
FAQ
Kiley surname: questions and answers
How many people in the U.S. have the surname Kiley?
Name Census estimates that about 6,371 living Americans carry the surname Kiley. Using the current population baseline, that works out to roughly 1 in 53,799 residents.
How common is Kiley?
Kiley ranks #5,966 in the 2020 Census surname tables and is classified on this site as "Rare." The Census recorded the name at a frequency of 1.86 per 100,000 residents, which is about 2 people out of every 100,000.
How many people with this surname were counted in the Census?
The raw 2020 Census file counted 5,556 people with the surname Kiley. That is different from the site's living-bearer estimate (6,371), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 1.86 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 1.86 per 100,000 means that if you picked a random group of 100,000 U.S. residents, you would expect about 2 of them to have the surname Kiley.
Has Kiley become more or less common over time?
Between 2010 and 2020, the surname Kiley went from 6,639 recorded bearers to 5,556. That is a decrease of 1,083 (-16.3%). In the national ranking it fell from #5,255 to #5,966.
What does the Census say about the background of Kiley?
Among Census respondents with the surname Kiley, the largest self-reported group is White at 91.5%. The next largest groups are Hispanic (3.1%) and Black (2.2%). 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 Kiley in the 2020 Census, accounting for 91.5% (5,085 people in the source table).
What is the full ancestry breakdown?
Kiley appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (91.5%), Hispanic (3.1%), Black (2.2%). 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 Kiley (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 Kiley mean?
An Anglicized form of the Irish surname Ó Caoile, meaning "descendant of Caol" (a personal name meaning "slender"). 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 Kiley (1.86 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 Kiley?
HowManyOfMe.org, our sister site, answers that with the living-bearer count in one glance.