2000
#12,868
National surname rank
Recorded bearers 2,192
First available Census row
Per 100,000 0.81
Rare Last name
Cullinan
An Irish surname derived from the Gaelic "O Cuileannain," meaning "descendant of Cuileannain," a personal name of uncertain meaning.
According to the 2020 US Census Bureau surname tables, roughly 2,370 Americans carry the last name Cullinan. That puts it at #13,967 in the national surname ranking, appearing at a frequency of 0.69 per 100,000 people (about 1 in 144,622 residents).
This page is the full Name Census profile for the Cullinan 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 Cullinan with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
2.4K
1 in 144,622
Census rank
#13,967
2020 decennial data
Per 100,000
0.7
Frequency rate
Recorded bearers
2.1K
rare in the US
Popularity narrative
The Census Bureau recorded 2,067 bearers of the surname Cullinan in its 2020 decennial surname file. At a rate of 0.69 per 100,000 residents, it holds the 13967th position in the national surname ranking.
Among Census respondents with the surname Cullinan, the largest self-reported group is White at 93.3%. The next largest groups are Hispanic (3.6%) and Two or More Races (1.9%).
Origin
Meaning and origin of Cullinan
The surname Cullinan originates from Ireland, where it first appeared in the 9th century. It is derived from the Gaelic words "cuil" meaning "angle" or "corner" and "Iomhain" meaning "a meadow." The name likely referred to someone who lived in a meadow or lived near a particular landmark.
The Cullinan surname is found predominantly in County Mayo, where it is considered a principal family name. The earliest recorded example of the name appears in the Annals of Ulster, an ancient Irish chronicle, in the year 845 AD, referring to a person named Culén mac Ailello.
In the 12th century, the surname is mentioned in the Book of Leinster, an important medieval Irish manuscript. The spelling "Cuillenayn" is used to refer to a family residing in the townland of Coolera, County Mayo.
Notable individuals with the surname Cullinan include Sir Thomas Cullinan (1564-1624), an Irish soldier and landowner who fought for the English crown during the Nine Years' War in Ireland. Another prominent figure was James Cullinan (1792-1879), an Irish engineer and inventor who devised a system for drilling artesian wells.
Perhaps the most famous bearer of the name was Thomas Cullinan (1838-1905), the South African mining magnate who discovered the Cullinan Diamond in 1905, the largest rough diamond ever found. This remarkable gem was eventually cut into several smaller diamonds, including the Great Star of Africa and the Lesser Star of Africa, which are part of the British Crown Jewels.
Other historical figures with the Cullinan surname include Michael Cullinan (1862-1940), an Irish politician and Member of Parliament, and Patrick Cullinan (1880-1960), an Irish Jesuit priest and scholar who specialized in Celtic studies.
While the Cullinan name has Irish roots, it has since spread to other parts of the world, particularly through emigration to countries like the United States, Canada, and Australia.
Demographics
Ancestry and ethnicity for Cullinan
Among Census respondents with the surname Cullinan, the largest self-reported group is White at 93.3%. The next largest groups are Hispanic (3.6%) and Two or More Races (1.9%).
The bar chart below shows how Cullinan 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 Cullinan surname at the time of the 2020 Census, not any inherent property of the name itself.
- White93.3% · 1,929
- Hispanic or Latino3.6% · 75
- Two or more races1.9% · 40
- Asian and Pacific Islander0.8% · 17
- Black or African American0.2% · 5
- American Indian and Alaska Native0.0% · 1
Timeline
Historical Census data for Cullinan
Cullinan 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
#13,306
National surname rank
Recorded bearers 2,292
+100 bearers (+4.6%)
Per 100,000 0.78
Rank movement Down 438 places
2020
#13,967
National surname rank
Recorded bearers 2,067
-225 bearers (-9.8%)
Per 100,000 0.69
Rank movement Down 661 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #12,868 | 2,192 | 0.81 | First available Census row | First available Census row |
| 2010 | #13,306 | 2,292 | 0.78 | +100 bearers (+4.6%) | Down 438 places |
| 2020 | #13,967 | 2,067 | 0.69 | -225 bearers (-9.8%) | Down 661 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 Cullinan 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 | #13,306 | #13,967 | -5.0% |
| Count | 2,292 | 2,067 | -9.8% |
| Per 100K | 0.78 | 0.69 | -11.3% |
Between the 2010 and 2020 Census, the number of Cullinan bearers went from 2,292 to 2,067 (-9.8% change). The surname moved down 661 positions in the national ranking, going from #13,306 to #13,967.
FAQ
Cullinan surname: questions and answers
How many people in the U.S. have the surname Cullinan?
Name Census estimates that about 2,370 living Americans carry the surname Cullinan. Using the current population baseline, that works out to roughly 1 in 144,622 residents.
How common is Cullinan?
Cullinan ranks #13,967 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 2,067 people with the surname Cullinan. That is different from the site's living-bearer estimate (2,370), 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 Cullinan.
Has Cullinan become more or less common over time?
Between 2010 and 2020, the surname Cullinan went from 2,292 recorded bearers to 2,067. That is a decrease of 225 (-9.8%). In the national ranking it fell from #13,306 to #13,967.
What does the Census say about the background of Cullinan?
Among Census respondents with the surname Cullinan, the largest self-reported group is White at 93.3%. The next largest groups are Hispanic (3.6%) and Two or More Races (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 Cullinan in the 2020 Census, accounting for 93.3% (1,929 people in the source table).
What is the full ancestry breakdown?
Cullinan appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (93.3%), Hispanic (3.6%), Two or More Races (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 Cullinan (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 Cullinan mean?
An Irish surname derived from the Gaelic "O Cuileannain," meaning "descendant of Cuileannain," a personal name of uncertain meaning. 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 Cullinan (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 many Americans have the surname Cullinan?
For a faster, more casual read, check HowManyOfMe.org — our sister site built around that single question.