2000
#113,519
National surname rank
Recorded bearers 143
First available Census row
Per 100,000 0.05
Very Rare Last name
Keill
A toponymic surname derived from the Scottish parish of Keill or Keills.
According to the 2020 US Census Bureau surname tables, roughly 117 Americans carry the last name Keill. That puts it at #154,755 in the national surname ranking, appearing at a frequency of 0.03 per 100,000 people (about 1 in 2,929,524 residents).
This page is the full Name Census profile for the Keill 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 Keill with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
117
1 in 2,929,524
Census rank
#154,755
2020 decennial data
Per 100,000
0.0
Frequency rate
Recorded bearers
102
very rare in the US
Popularity narrative
The Census Bureau recorded 102 bearers of the surname Keill in its 2020 decennial surname file. At a rate of 0.03 per 100,000 residents, it holds the 154755th position in the national surname ranking.
Among Census respondents with the surname Keill, the largest self-reported group is White at 97.1%. The next largest groups are Hispanic (1.0%) and American Indian/Alaska Native (1.0%).
Origin
Meaning and origin of Keill
The surname Keill originated in Scotland, with its earliest known records dating back to the 16th century. It is believed to have derived from the Gaelic word "caol," meaning "narrow" or "slender," which may have been used to describe a person's physical appearance or the location of a place inhabited by the family.
One of the earliest documented instances of the name Keill can be found in the "Register of the Privy Seal of Scotland" from 1544, which mentions a "John Keill" from the county of Ayrshire. This suggests that the name may have been concentrated in the southwestern regions of Scotland during its early years.
In the late 16th and early 17th centuries, several Keill families were recorded in the parish registers of Kirkcudbrightshire and Wigtownshire, indicating a potential spread of the name to the southern regions of Scotland during this period.
A notable bearer of the Keill surname was John Keill (1671-1721), a Scottish mathematician and astronomer who made significant contributions to the field of celestial mechanics. He was born in Edinburgh and served as the first Savilian Professor of Astronomy at the University of Oxford from 1712 until his death.
Another individual of historical importance was James Keill (1673-1719), a Scottish physician and philosopher who was a proponent of Newtonian physics. He authored the influential work "An Introduction to Natural Philosophy" and served as the Regius Professor of Medicine at the University of Cambridge.
In the 18th century, the Keill surname appeared in various records across Scotland, with families residing in areas such as Ayrshire, Lanarkshire, and Renfrewshire. One notable example is John Keill (1727-1796), a Scottish poet and playwright born in Campbeltown, Argyllshire, who wrote several works including the tragedy "Sir William Wallace."
The name Keill has also been associated with various place names in Scotland, such as Keillour in Perthshire and Keills in Argyllshire, which may have contributed to the surname's development and spread throughout the country.
While the Keill surname has its roots firmly planted in Scotland, it has since been carried to other parts of the world through migration and immigration. However, its origins and earliest recorded instances remain firmly tied to the Scottish landscape and its rich cultural heritage.
Demographics
Ancestry and ethnicity for Keill
Among Census respondents with the surname Keill, the largest self-reported group is White at 97.1%. The next largest groups are Hispanic (1.0%) and American Indian/Alaska Native (1.0%).
The bar chart below shows how Keill 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 Keill surname at the time of the 2020 Census, not any inherent property of the name itself.
- White97.1% · 99
- Hispanic or Latino1.0% · 1
- American Indian and Alaska Native1.0% · 1
- Two or more races1.0% · 1
Timeline
Historical Census data for Keill
Keill 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
#149,395
National surname rank
Recorded bearers 110
-33 bearers (-23.1%)
Per 100,000 0.04
Rank movement Down 35,876 places
2020
#154,755
National surname rank
Recorded bearers 102
-8 bearers (-7.3%)
Per 100,000 0.03
Rank movement Down 5,360 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #113,519 | 143 | 0.05 | First available Census row | First available Census row |
| 2010 | #149,395 | 110 | 0.04 | -33 bearers (-23.1%) | Down 35,876 places |
| 2020 | #154,755 | 102 | 0.03 | -8 bearers (-7.3%) | Down 5,360 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 Keill 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 | #149,395 | #154,755 | -3.6% |
| Count | 110 | 102 | -7.3% |
| Per 100K | 0.04 | 0.03 | -14.7% |
Between the 2010 and 2020 Census, the number of Keill bearers went from 110 to 102 (-7.3% change). The surname moved down 5,360 positions in the national ranking, going from #149,395 to #154,755.
FAQ
Keill surname: questions and answers
How many people in the U.S. have the surname Keill?
Name Census estimates that about 117 living Americans carry the surname Keill. Using the current population baseline, that works out to roughly 1 in 2,929,524 residents.
How common is Keill?
Keill ranks #154,755 in the 2020 Census surname tables and is classified on this site as "Very Rare." The Census recorded the name at a frequency of 0.03 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 102 people with the surname Keill. That is different from the site's living-bearer estimate (117), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 0.03 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 0.03 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 Keill.
Has Keill become more or less common over time?
Between 2010 and 2020, the surname Keill went from 110 recorded bearers to 102. That is a decrease of 8 (-7.3%). In the national ranking it fell from #149,395 to #154,755.
What does the Census say about the background of Keill?
Among Census respondents with the surname Keill, the largest self-reported group is White at 97.1%. The next largest groups are Hispanic (1.0%) and American Indian/Alaska Native (1.0%). 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 Keill in the 2020 Census, accounting for 97.1% (99 people in the source table).
What is the full ancestry breakdown?
Keill appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (97.1%), Hispanic (1.0%), American Indian/Alaska Native (1.0%). 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 Keill (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 Keill mean?
A toponymic surname derived from the Scottish parish of Keill or Keills. 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 Keill (0.03 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 Keill?
You can see how many people have the surname Keill on our sister site HowManyOfMe.org — same data roots, lighter UI.