2010
#158,432
National surname rank
Recorded bearers 102
First available Census row
Per 100,000 0.03
Very Rare Last name
Rhyu
Possibly from a Korean surname originated as the rendering of a Mongolian title.
According to the 2020 US Census Bureau surname tables, roughly 126 Americans carry the last name Rhyu. That puts it at #149,446 in the national surname ranking, appearing at a frequency of 0.04 per 100,000 people (about 1 in 2,720,273 residents).
This page is the full Name Census profile for the Rhyu 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
126
1 in 2,720,273
Census rank
#149,446
2020 decennial data
Per 100,000
0.0
Frequency rate
Recorded bearers
110
very rare in the US
Popularity narrative
The Census Bureau recorded 110 bearers of the surname Rhyu in its 2020 decennial surname file. At a rate of 0.04 per 100,000 residents, it holds the 149446th position in the national surname ranking.
Among Census respondents with the surname Rhyu, the largest self-reported group is Asian/Pacific Islander at 86.4%. The next largest groups are Two or More Races (9.1%) and White (2.7%).
Origin
Meaning and origin of Rhyu
The surname RHYU has its origins in the Korean peninsula, emerging around the 6th century during the Three Kingdoms period. It is believed to be derived from the ancient Korean word "rhyu," which means "flowing water" or "stream." This likely indicates that the name originated among a clan or group residing near a river or waterway in what is now modern-day South Korea.
One of the earliest recorded references to the name RHYU can be found in the Samguk Sagi, a historical record compiled in 1145 during the Goryeo dynasty. The text mentions a prominent figure named RHYU Seung-won, who served as a military commander and advisor to King Sinmun in the 7th century.
During the Joseon dynasty, which ruled from 1392 to 1897, the RHYU surname gained further prominence. Records from this period show that the name was concentrated in the Gyeongsang and Jeolla provinces, particularly in the areas around the Nakdong River and its tributaries.
In the 16th century, a notable RHYU was RHYU Seong-ryong (1542-1607), a revered Confucian scholar and writer who served as a royal tutor and advisor to King Seonjo. His works on ethics and governance were widely studied by the Joseon aristocracy.
Another significant figure from this era was RHYU Gwan-sun (1556-1618), a skilled military strategist and general who played a crucial role in defending Korea against Japanese invasions in the late 16th century.
Moving into the 19th century, RHYU Byeong-hyu (1819-1885) was a prominent statesman and diplomat who served as a Korean envoy to China and Japan. He played a pivotal role in navigating Korea's relations with its neighboring powers during a period of rapid change and modernization.
A more contemporary figure was RHYU Deok-gyu (1898-1962), a celebrated poet and writer who was a leading voice in the Korean literary renaissance of the early 20th century. His works explored themes of national identity, tradition, and the struggles of the Korean people during the Japanese colonial period.
While the RHYU surname may have evolved in spelling or pronunciation over the centuries, its origins can be traced back to the ancient waterways of the Korean peninsula, reflecting the deep connection between this family name and the natural landscapes that shaped the region's history and culture.
Demographics
Ancestry and ethnicity for Rhyu
Among Census respondents with the surname Rhyu, the largest self-reported group is Asian/Pacific Islander at 86.4%. The next largest groups are Two or More Races (9.1%) and White (2.7%).
The bar chart below shows how Rhyu 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 Rhyu surname at the time of the 2020 Census, not any inherent property of the name itself.
- Asian and Pacific Islander86.4% · 95
- Two or more races9.1% · 10
- White2.7% · 3
- Black or African American0.9% · 1
- Hispanic or Latino0.9% · 1
Timeline
Historical Census data for Rhyu
Rhyu appears in 2 published Census surname files: 2010, 2020. The cards below show how the name's rank and bearer count changed across each release.
2020
#149,446
National surname rank
Recorded bearers 110
+8 bearers (+7.8%)
Per 100,000 0.04
Rank movement Up 8,986 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2010 | #158,432 | 102 | 0.03 | First available Census row | First available Census row |
| 2020 | #149,446 | 110 | 0.04 | +8 bearers (+7.8%) | Up 8,986 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 Rhyu 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 | #158,432 | #149,446 | 5.7% |
| Count | 102 | 110 | 7.8% |
| Per 100K | 0.03 | 0.04 | 22.7% |
Between the 2010 and 2020 Census, the number of Rhyu bearers went from 102 to 110 (+7.8% change). The surname moved up 8,986 positions in the national ranking, going from #158,432 to #149,446.
FAQ
Rhyu surname: questions and answers
How many people in the U.S. have the surname Rhyu?
Name Census estimates that about 126 living Americans carry the surname Rhyu. Using the current population baseline, that works out to roughly 1 in 2,720,273 residents.
How common is Rhyu?
Rhyu ranks #149,446 in the 2020 Census surname tables and is classified on this site as "Very Rare." The Census recorded the name at a frequency of 0.04 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 110 people with the surname Rhyu. That is different from the site's living-bearer estimate (126), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 0.04 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 0.04 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 Rhyu.
Has Rhyu become more or less common over time?
Between 2010 and 2020, the surname Rhyu went from 102 recorded bearers to 110. That is an increase of 8 (+7.8%). In the national ranking it rose from #158,432 to #149,446.
What does the Census say about the background of Rhyu?
Among Census respondents with the surname Rhyu, the largest self-reported group is Asian/Pacific Islander at 86.4%. The next largest groups are Two or More Races (9.1%) and White (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 Rhyu in the 2020 Census, accounting for 86.4% (95 people in the source table).
What is the full ancestry breakdown?
Rhyu appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are Asian/Pacific Islander (86.4%), Two or More Races (9.1%), White (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 Rhyu (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 Rhyu mean?
Possibly from a Korean surname originated as the rendering of a Mongolian title. 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 Rhyu (0.04 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 Rhyu?
For a faster, more casual read, check HowManyOfMe.org — our sister site built around that single question.