2000
#39,824
National surname rank
Recorded bearers 519
First available Census row
Per 100,000 0.19
Rare Last name
Oo
A surname denoting an ancestor who lived on higher ground or an elevated place.
According to the 2020 US Census Bureau surname tables, roughly 3,979 Americans carry the last name Oo. That puts it at #9,035 in the national surname ranking, appearing at a frequency of 1.16 per 100,000 people (about 1 in 86,141 residents).
This page is the full Name Census profile for the Oo 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 Oo with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
4.0K
1 in 86,141
Census rank
#9,035
2020 decennial data
Per 100,000
1.2
Frequency rate
Recorded bearers
3.5K
rare in the US
Popularity narrative
The Census Bureau recorded 3,470 bearers of the surname Oo in its 2020 decennial surname file. At a rate of 1.16 per 100,000 residents, it holds the 9035th position in the national surname ranking.
Among Census respondents with the surname Oo, the largest self-reported group is Asian/Pacific Islander at 93.8%. The next largest groups are White (2.6%) and Hispanic (1.3%).
Origin
Meaning and origin of Oo
The surname "OO" is believed to have originated in China, with records dating back to the Tang Dynasty (618-907 CE). It is thought to be derived from the Chinese word "wu", which means "black" or "dark". This name was initially used to describe a person's physical appearance or complexion.
One of the earliest known instances of the name "OO" can be found in the "Book of Tang", a historical record compiled in the late 10th century CE. It mentions a scholar named Oo Zhenren, who lived during the Tang Dynasty and was renowned for his expertise in calligraphy and literature.
During the Song Dynasty (960-1279 CE), the name "OO" became more widespread, particularly in the regions of Zhejiang and Jiangsu provinces. It is believed that some families adopted this surname due to its association with the imperial family, as the word "wu" was also used to refer to the color black, which was considered a symbol of power and nobility.
In the Ming Dynasty (1368-1644 CE), the name "OO" gained further recognition with the emergence of several influential figures. One notable example is Oo Xianxian (1516-1593), a renowned scholar and philosopher who made significant contributions to the development of Neo-Confucianism.
Another prominent individual bearing the surname "OO" was Oo Qizhou (1565-1627), a general and military strategist who played a crucial role in suppressing the peasant uprisings during the late Ming Dynasty.
During the Qing Dynasty (1644-1912 CE), the name "OO" continued to be prevalent, particularly in the northern regions of China. One noteworthy figure from this period was Oo Renchu (1773-1858), a scholar and poet who was highly regarded for his works on classical Chinese literature.
In modern times, the surname "OO" has spread across various parts of the world due to Chinese immigration and diaspora. Some notable individuals with this surname include Oo Yeong-ming (1917-2001), a Taiwanese novelist and essayist, and Oo Shu-chen (born 1957), a Taiwanese politician and former Vice President of Taiwan.
Demographics
Ancestry and ethnicity for Oo
Among Census respondents with the surname Oo, the largest self-reported group is Asian/Pacific Islander at 93.8%. The next largest groups are White (2.6%) and Hispanic (1.3%).
The bar chart below shows how Oo 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 Oo surname at the time of the 2020 Census, not any inherent property of the name itself.
- Asian and Pacific Islander93.8% · 3,254
- White2.6% · 90
- Hispanic or Latino1.3% · 46
- Black or African American1.2% · 42
- Two or more races1.0% · 36
- American Indian and Alaska Native0.1% · 2
Timeline
Historical Census data for Oo
Oo 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
#17,565
National surname rank
Recorded bearers 1,601
+1,082 bearers (+208.5%)
Per 100,000 0.54
Rank movement Up 22,259 places
2020
#9,035
National surname rank
Recorded bearers 3,470
+1,869 bearers (+116.7%)
Per 100,000 1.16
Rank movement Up 8,530 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #39,824 | 519 | 0.19 | First available Census row | First available Census row |
| 2010 | #17,565 | 1,601 | 0.54 | +1,082 bearers (+208.5%) | Up 22,259 places |
| 2020 | #9,035 | 3,470 | 1.16 | +1,869 bearers (+116.7%) | Up 8,530 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 Oo 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 | #17,565 | #9,035 | 48.6% |
| Count | 1,601 | 3,470 | 116.7% |
| Per 100K | 0.54 | 1.16 | 115.0% |
Between the 2010 and 2020 Census, the number of Oo bearers went from 1,601 to 3,470 (+116.7% change). The surname moved up 8,530 positions in the national ranking, going from #17,565 to #9,035.
FAQ
Oo surname: questions and answers
How many people in the U.S. have the surname Oo?
Name Census estimates that about 3,979 living Americans carry the surname Oo. Using the current population baseline, that works out to roughly 1 in 86,141 residents.
How common is Oo?
Oo ranks #9,035 in the 2020 Census surname tables and is classified on this site as "Rare." The Census recorded the name at a frequency of 1.16 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 3,470 people with the surname Oo. That is different from the site's living-bearer estimate (3,979), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 1.16 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 1.16 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 Oo.
Has Oo become more or less common over time?
Between 2010 and 2020, the surname Oo went from 1,601 recorded bearers to 3,470. That is an increase of 1,869 (+116.7%). In the national ranking it rose from #17,565 to #9,035.
What does the Census say about the background of Oo?
Among Census respondents with the surname Oo, the largest self-reported group is Asian/Pacific Islander at 93.8%. The next largest groups are White (2.6%) and Hispanic (1.3%). 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 Oo in the 2020 Census, accounting for 93.8% (3,254 people in the source table).
What is the full ancestry breakdown?
Oo appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are Asian/Pacific Islander (93.8%), White (2.6%), Hispanic (1.3%). 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 Oo (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 Oo mean?
A surname denoting an ancestor who lived on higher ground or an elevated place. 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 Oo (1.16 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 share the surname Oo?
For a faster, more casual read, check HowManyOfMe.org — our sister site built around that single question.