2000
#15,652
National surname rank
Recorded bearers 1,714
First available Census row
Per 100,000 0.64
Rare Last name
Co
A Vietnamese surname derived from the Chinese surname Cao, meaning "tall" or "high."
According to the 2020 US Census Bureau surname tables, roughly 3,270 Americans carry the last name Co. That puts it at #10,704 in the national surname ranking, appearing at a frequency of 0.95 per 100,000 people (about 1 in 104,818 residents).
This page is the full Name Census profile for the Co 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 Co with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
3.3K
1 in 104,818
Census rank
#10,704
2020 decennial data
Per 100,000
1.0
Frequency rate
Recorded bearers
2.9K
rare in the US
Popularity narrative
The Census Bureau recorded 2,852 bearers of the surname Co in its 2020 decennial surname file. At a rate of 0.95 per 100,000 residents, it holds the 10704th position in the national surname ranking.
Among Census respondents with the surname Co, the largest self-reported group is Asian/Pacific Islander at 79.2%. The next largest groups are White (9.9%) and Hispanic (4.5%).
Origin
Meaning and origin of Co
The surname Co has its origins in northern Italy, dating back to the 12th century. It is believed to have derived from the Italian word "collo," meaning "neck" or "hill." This suggests that the name may have originally referred to someone who lived on a hill or a person with a distinctive neck.
One of the earliest recorded instances of the surname Co can be found in the Codice Diplomatico Longobardo, a collection of legal documents from the Lombard period in Italy, which dates back to the 8th century. The name appears in various forms, such as "Collo" and "Colo."
In the 13th century, the name Co gained prominence in the city of Genoa, where several notable individuals bore this surname. One of the earliest recorded examples is Giovanni Co, a merchant and banker who lived in the late 1200s. Another notable figure was Marco Co, a renowned navigator and explorer who participated in several expeditions to the Mediterranean and the Black Sea in the early 14th century.
The surname Co also has strong ties to the island of Sardinia, where it is believed to have originated from the Sardinian word "coghiu," meaning "hill" or "slope." In the 15th century, the name appears in several historical records from the region, including the Codice Cartaceo di Arborea, a collection of documents related to the Giudicato of Arborea, a sovereign state that existed on the island from the 10th to the 15th century.
One of the most famous individuals with the surname Co was Girolamo Co, a Sardinian poet and playwright who lived in the late 16th century. His works, such as the pastoral play "S'Arrescogghida," are considered among the earliest examples of Sardinian literature.
In the 17th century, the name Co spread to other parts of Italy, including the regions of Lombardy and Veneto. Notable figures from this period include Giacomo Co, a Venetian architect who designed several notable buildings in the city, including the Church of Santa Maria dei Derelitti.
Other notable individuals with the surname Co throughout history include Vincenzo Co, an Italian painter and sculptor from the 18th century, known for his works in the Baroque style; Antonio Co, a 19th-century Italian mathematician and physicist who made significant contributions to the study of electromagnetism; and Emilio Co, a 20th-century Italian footballer who played for several clubs in Italy and represented the national team in the 1930s.
Demographics
Ancestry and ethnicity for Co
Among Census respondents with the surname Co, the largest self-reported group is Asian/Pacific Islander at 79.2%. The next largest groups are White (9.9%) and Hispanic (4.5%).
The bar chart below shows how Co 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 Co surname at the time of the 2020 Census, not any inherent property of the name itself.
- Asian and Pacific Islander79.2% · 2,260
- White9.9% · 281
- Hispanic or Latino4.5% · 127
- Two or more races4.1% · 117
- Black or African American2.3% · 65
- American Indian and Alaska Native0.1% · 2
Timeline
Historical Census data for Co
Co 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
#11,846
National surname rank
Recorded bearers 2,642
+928 bearers (+54.1%)
Per 100,000 0.90
Rank movement Up 3,806 places
2020
#10,704
National surname rank
Recorded bearers 2,852
+210 bearers (+7.9%)
Per 100,000 0.95
Rank movement Up 1,142 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #15,652 | 1,714 | 0.64 | First available Census row | First available Census row |
| 2010 | #11,846 | 2,642 | 0.90 | +928 bearers (+54.1%) | Up 3,806 places |
| 2020 | #10,704 | 2,852 | 0.95 | +210 bearers (+7.9%) | Up 1,142 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 Co 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 | #11,846 | #10,704 | 9.6% |
| Count | 2,642 | 2,852 | 7.9% |
| Per 100K | 0.90 | 0.95 | 6.0% |
Between the 2010 and 2020 Census, the number of Co bearers went from 2,642 to 2,852 (+7.9% change). The surname moved up 1,142 positions in the national ranking, going from #11,846 to #10,704.
FAQ
Co surname: questions and answers
How many people in the U.S. have the surname Co?
Name Census estimates that about 3,270 living Americans carry the surname Co. Using the current population baseline, that works out to roughly 1 in 104,818 residents.
How common is Co?
Co ranks #10,704 in the 2020 Census surname tables and is classified on this site as "Rare." The Census recorded the name at a frequency of 0.95 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 2,852 people with the surname Co. That is different from the site's living-bearer estimate (3,270), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 0.95 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 0.95 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 Co.
Has Co become more or less common over time?
Between 2010 and 2020, the surname Co went from 2,642 recorded bearers to 2,852. That is an increase of 210 (+7.9%). In the national ranking it rose from #11,846 to #10,704.
What does the Census say about the background of Co?
Among Census respondents with the surname Co, the largest self-reported group is Asian/Pacific Islander at 79.2%. The next largest groups are White (9.9%) and Hispanic (4.5%). 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 Co in the 2020 Census, accounting for 79.2% (2,260 people in the source table).
What is the full ancestry breakdown?
Co appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are Asian/Pacific Islander (79.2%), White (9.9%), Hispanic (4.5%). 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 Co (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 Co mean?
A Vietnamese surname derived from the Chinese surname Cao, meaning "tall" or "high." 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 Co (0.95 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 Co?
For a faster, more casual read, check HowManyOfMe.org — our sister site built around that single question.