2000
#12,945
National surname rank
Recorded bearers 2,174
First available Census row
Per 100,000 0.81
Rare Last name
Joo
A Korean surname derived from the Hanja character meaning "Zhou," an ancient Chinese state.
According to the 2020 US Census Bureau surname tables, roughly 3,731 Americans carry the last name Joo. That puts it at #9,554 in the national surname ranking, appearing at a frequency of 1.09 per 100,000 people (about 1 in 91,867 residents).
This page is the full Name Census profile for the Joo 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.
Bearers in the US
3.7K
1 in 91,867
Census rank
#9,554
2020 decennial data
Per 100,000
1.1
Frequency rate
Recorded bearers
3.3K
rare in the US
Popularity narrative
The Census Bureau recorded 3,254 bearers of the surname Joo in its 2020 decennial surname file. At a rate of 1.09 per 100,000 residents, it holds the 9554th position in the national surname ranking.
Among Census respondents with the surname Joo, the largest self-reported group is Asian/Pacific Islander at 88.0%. The next largest groups are White (6.5%) and Hispanic (2.7%).
Origin
Meaning and origin of Joo
The surname Joo originated in Korea during the 14th century. It is derived from the Korean word "ju," meaning "lord" or "master." The earliest known records of the Joo surname can be found in the Goryeo Dynasty (918-1392) royal chronicles, where it was often associated with members of the noble class or high-ranking government officials.
One of the earliest documented individuals with the Joo surname was Joo Yeong-su (1337-1392), a prominent scholar and politician during the late Goryeo period. He served as a chief minister under King Gongmin and played a significant role in establishing the neo-Confucian ideology that would shape Korean society for centuries.
During the Joseon Dynasty (1392-1897), the Joo surname became widely distributed throughout the Korean peninsula. Several notable figures emerged, including Joo Se-bung (1495-1554), a renowned Neo-Confucian scholar and writer who authored various influential works on philosophy and ethics.
Another prominent individual was Joo Hang (1786-1834), a dedicated scholar and educator who established the Gyeongsang Confucian Academy, which played a vital role in preserving and promoting traditional Korean Confucian values and education.
In the realm of literature, Joo Yi-hang (1809-1857) was a celebrated poet and writer during the late Joseon period. His works, particularly his lyrical poetry, are regarded as some of the finest examples of traditional Korean literature.
Throughout history, the Joo surname has also been associated with various place names, such as Joo-am, a village in the Gyeonggi province, and Joo-seong, an ancient fortress located in the present-day city of Jeonju.
While the Joo surname has deep roots in Korean history, it has also found its way into other parts of the world, particularly among Korean diasporas. Individuals with this surname have made significant contributions in various fields, further enriching the legacy of this ancient Korean name.
Demographics
Ancestry and ethnicity for Joo
Among Census respondents with the surname Joo, the largest self-reported group is Asian/Pacific Islander at 88.0%. The next largest groups are White (6.5%) and Hispanic (2.7%).
The bar chart below shows how Joo 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 Joo surname at the time of the 2020 Census, not any inherent property of the name itself.
- Asian and Pacific Islander88.0% · 2,864
- White6.5% · 211
- Hispanic or Latino2.7% · 87
- Two or more races1.9% · 61
- Black or African American0.8% · 27
- American Indian and Alaska Native0.1% · 4
Timeline
Historical Census data for Joo
Joo 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
#10,324
National surname rank
Recorded bearers 3,121
+947 bearers (+43.6%)
Per 100,000 1.06
Rank movement Up 2,621 places
2020
#9,554
National surname rank
Recorded bearers 3,254
+133 bearers (+4.3%)
Per 100,000 1.09
Rank movement Up 770 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #12,945 | 2,174 | 0.81 | First available Census row | First available Census row |
| 2010 | #10,324 | 3,121 | 1.06 | +947 bearers (+43.6%) | Up 2,621 places |
| 2020 | #9,554 | 3,254 | 1.09 | +133 bearers (+4.3%) | Up 770 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 Joo 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 | #10,324 | #9,554 | 7.5% |
| Count | 3,121 | 3,254 | 4.3% |
| Per 100K | 1.06 | 1.09 | 2.7% |
Between the 2010 and 2020 Census, the number of Joo bearers went from 3,121 to 3,254 (+4.3% change). The surname moved up 770 positions in the national ranking, going from #10,324 to #9,554.
FAQ
Joo surname: questions and answers
How many people in the U.S. have the surname Joo?
Name Census estimates that about 3,731 living Americans carry the surname Joo. Using the current population baseline, that works out to roughly 1 in 91,867 residents.
How common is Joo?
Joo ranks #9,554 in the 2020 Census surname tables and is classified on this site as "Rare." The Census recorded the name at a frequency of 1.09 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 3,254 people with the surname Joo. That is different from the site's living-bearer estimate (3,731), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 1.09 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 1.09 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 Joo.
Has Joo become more or less common over time?
Between 2010 and 2020, the surname Joo went from 3,121 recorded bearers to 3,254. That is an increase of 133 (+4.3%). In the national ranking it rose from #10,324 to #9,554.
What does the Census say about the background of Joo?
Among Census respondents with the surname Joo, the largest self-reported group is Asian/Pacific Islander at 88.0%. The next largest groups are White (6.5%) and Hispanic (2.7%). 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?
Asian/Pacific Islander is the largest self-reported group for the surname Joo in the 2020 Census, accounting for 88.0% (2,864 people in the source table).
What is the full ancestry breakdown?
Joo appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are Asian/Pacific Islander (88.0%), White (6.5%), Hispanic (2.7%). 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 Joo (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 Joo mean?
A Korean surname derived from the Hanja character meaning "Zhou," an ancient Chinese state. 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 Joo (1.09 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 Joo?
For a faster, more casual read, check HowManyOfMe.org — our sister site built around that single question.