2000
#4,278
National surname rank
Recorded bearers 7,672
First available Census row
Per 100,000 2.84
Rare Last name
Kozak
A Polish and Ukrainian occupational surname referring to a Cossack, a member of a self-governing military community.
According to the 2020 US Census Bureau surname tables, roughly 8,419 Americans carry the last name Kozak. That puts it at #4,686 in the national surname ranking, appearing at a frequency of 2.46 per 100,000 people (about 1 in 40,712 residents).
This page is the full Name Census profile for the Kozak 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 Kozak with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
8.4K
1 in 40,712
Census rank
#4,686
2020 decennial data
Per 100,000
2.5
Frequency rate
Recorded bearers
7.3K
rare in the US
Popularity narrative
The Census Bureau recorded 7,342 bearers of the surname Kozak in its 2020 decennial surname file. At a rate of 2.46 per 100,000 residents, it holds the 4686th position in the national surname ranking.
Among Census respondents with the surname Kozak, the largest self-reported group is White at 94.0%. The next largest groups are Hispanic (3.0%) and Two or More Races (1.9%).
Origin
Meaning and origin of Kozak
The surname Kozak is of Ukrainian and Polish origin, dating back to the 16th century. It is derived from the Ukrainian and Polish word "kozak," which means a free man or a member of the Cossack military communities.
The Cossacks were semi-nomadic people who lived in the steppes of present-day Ukraine and southern Russia. They were known for their horsemanship, military prowess, and fiercely independent spirit. The name Kozak was likely given to individuals who were associated with or members of these Cossack communities.
One of the earliest recorded mentions of the name Kozak can be found in the Polish noble registry known as the "Metryka Koronna" from the 16th century. It lists several individuals with the surname Kozak, indicating that the name was already in use during that time period.
In the 17th century, the Cossacks played a significant role in the Khmelnytsky Uprising, a major rebellion against Polish rule in Ukraine. One notable figure from this era was Bohdan Khmelnytsky (1595-1657), a Cossack leader who led the uprising and established the Cossack Hetmanate, a semi-autonomous state in Ukraine.
Another prominent individual with the surname Kozak was Semen Kozak (1652-1708), a Ukrainian military leader and diplomat who served as the secretary of the Zaporozhian Host, a Cossack military organization.
In the 19th century, the name Kozak was associated with the Kuban Cossacks, a Cossack community that settled in the Kuban region of Russia. One famous Kuban Cossack was Kondrat Kozak (1810-1879), a military leader and hero of the Caucasian War.
Over time, the surname Kozak spread beyond its initial Ukrainian and Polish roots, and individuals with this name can be found in various parts of Europe and the Americas, likely due to migration and diaspora communities.
Other notable individuals with the surname Kozak include Jerzy Kozak (1957-2020), a Polish diplomat and politician who served as the Minister of Foreign Affairs of Poland from 2005 to 2006, and Sergei Kozak (born 1959), a Russian politician and former Deputy Prime Minister of Russia.
Demographics
Ancestry and ethnicity for Kozak
Among Census respondents with the surname Kozak, the largest self-reported group is White at 94.0%. The next largest groups are Hispanic (3.0%) and Two or More Races (1.9%).
The bar chart below shows how Kozak 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 Kozak surname at the time of the 2020 Census, not any inherent property of the name itself.
- White94.0% · 6,901
- Hispanic or Latino3.0% · 219
- Two or more races1.9% · 142
- Asian and Pacific Islander0.6% · 44
- Black or African American0.3% · 22
- American Indian and Alaska Native0.2% · 14
Timeline
Historical Census data for Kozak
Kozak 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
#4,733
National surname rank
Recorded bearers 7,495
-177 bearers (-2.3%)
Per 100,000 2.54
Rank movement Down 455 places
2020
#4,686
National surname rank
Recorded bearers 7,342
-153 bearers (-2.0%)
Per 100,000 2.46
Rank movement Up 47 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #4,278 | 7,672 | 2.84 | First available Census row | First available Census row |
| 2010 | #4,733 | 7,495 | 2.54 | -177 bearers (-2.3%) | Down 455 places |
| 2020 | #4,686 | 7,342 | 2.46 | -153 bearers (-2.0%) | Up 47 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 Kozak 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 | #4,733 | #4,686 | 1.0% |
| Count | 7,495 | 7,342 | -2.0% |
| Per 100K | 2.54 | 2.46 | -3.3% |
Between the 2010 and 2020 Census, the number of Kozak bearers went from 7,495 to 7,342 (-2.0% change). The surname moved up 47 positions in the national ranking, going from #4,733 to #4,686.
FAQ
Kozak surname: questions and answers
How many people in the U.S. have the surname Kozak?
Name Census estimates that about 8,419 living Americans carry the surname Kozak. Using the current population baseline, that works out to roughly 1 in 40,712 residents.
How common is Kozak?
Kozak ranks #4,686 in the 2020 Census surname tables and is classified on this site as "Rare." The Census recorded the name at a frequency of 2.46 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 7,342 people with the surname Kozak. That is different from the site's living-bearer estimate (8,419), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 2.46 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 2.46 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 Kozak.
Has Kozak become more or less common over time?
Between 2010 and 2020, the surname Kozak went from 7,495 recorded bearers to 7,342. That is a decrease of 153 (-2.0%). In the national ranking it rose from #4,733 to #4,686.
What does the Census say about the background of Kozak?
Among Census respondents with the surname Kozak, the largest self-reported group is White at 94.0%. The next largest groups are Hispanic (3.0%) 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 Kozak in the 2020 Census, accounting for 94.0% (6,901 people in the source table).
What is the full ancestry breakdown?
Kozak appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (94.0%), Hispanic (3.0%), 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 Kozak (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 Kozak mean?
A Polish and Ukrainian occupational surname referring to a Cossack, a member of a self-governing military community. 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 Kozak (2.46 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 have the surname Kozak?
For a faster, more casual read, check HowManyOfMe.org — our sister site built around that single question.