2000
#4,616
National surname rank
Recorded bearers 7,027
First available Census row
Per 100,000 2.60
Rare Last name
Aguiar
A Galician and Portuguese habitational surname referring to someone who lived near a field or open space.
According to the 2020 US Census Bureau surname tables, roughly 9,892 Americans carry the last name Aguiar. That puts it at #3,994 in the national surname ranking, appearing at a frequency of 2.89 per 100,000 people (about 1 in 34,650 residents).
This page is the full Name Census profile for the Aguiar 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 Aguiar with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
9.9K
1 in 34,650
Census rank
#3,994
2020 decennial data
Per 100,000
2.9
Frequency rate
Recorded bearers
8.6K
rare in the US
Popularity narrative
The Census Bureau recorded 8,626 bearers of the surname Aguiar in its 2020 decennial surname file. At a rate of 2.89 per 100,000 residents, it holds the 3994th position in the national surname ranking.
Among Census respondents with the surname Aguiar, the largest self-reported group is Hispanic at 47.8%. The next largest groups are White (46.8%) and Two or More Races (2.2%).
Origin
Meaning and origin of Aguiar
The surname Aguiar is believed to have originated in Portugal, where it is most commonly found. It is derived from the Portuguese word "agua," meaning water, suggesting that the name may have been given to someone who lived near a body of water or worked with water in some capacity.
The earliest recorded instances of the Aguiar surname date back to the 12th and 13th centuries in Portugal. Some historical records from this time period mention individuals with the name, such as João de Aguiar, a nobleman who lived in the 13th century.
In the 15th century, the name appeared in various Portuguese manuscripts and documents, including records of land ownership and noble families. For example, the Aguiar family was a prominent noble lineage during this time, with members holding important positions in the Portuguese court and military.
One notable individual with the surname Aguiar was Tomé de Aguiar, a Portuguese explorer and navigator who lived in the 16th century. He participated in several voyages to South America and Africa, contributing to the expansion of Portuguese exploration and trade.
The Aguiar surname is also associated with various place names in Portugal, such as Aguiar da Beira, a municipality in the Guarda District, and Aguiar de Sousa, a parish in the Porto District. These place names likely derived from the word "agua" as well, indicating the presence of water sources in those areas.
Throughout history, several other individuals with the surname Aguiar have made significant contributions in various fields. Manuel Aguiar, a 17th-century Portuguese painter, was known for his religious works. António Ribeiro de Aguiar, a 19th-century Brazilian politician and lawyer, played a prominent role in the independence movement of Brazil.
In more recent times, Fernando Aguiar, a 20th-century Portuguese sculptor and artist, gained recognition for his abstract and modernist works. Additionally, Miguel Aguiar, a contemporary Portuguese mathematician and physicist, has made notable contributions to the field of systems biology and complex systems.
Demographics
Ancestry and ethnicity for Aguiar
Among Census respondents with the surname Aguiar, the largest self-reported group is Hispanic at 47.8%. The next largest groups are White (46.8%) and Two or More Races (2.2%).
The bar chart below shows how Aguiar 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 Aguiar surname at the time of the 2020 Census, not any inherent property of the name itself.
- Hispanic or Latino47.8% · 4,119
- White46.8% · 4,039
- Two or more races2.2% · 186
- Asian and Pacific Islander2.0% · 176
- Black or African American1.1% · 93
- American Indian and Alaska Native0.2% · 13
Timeline
Historical Census data for Aguiar
Aguiar 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
#4,227
National surname rank
Recorded bearers 8,390
+1,363 bearers (+19.4%)
Per 100,000 2.84
Rank movement Up 389 places
2020
#3,994
National surname rank
Recorded bearers 8,626
+236 bearers (+2.8%)
Per 100,000 2.89
Rank movement Up 233 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #4,616 | 7,027 | 2.60 | First available Census row | First available Census row |
| 2010 | #4,227 | 8,390 | 2.84 | +1,363 bearers (+19.4%) | Up 389 places |
| 2020 | #3,994 | 8,626 | 2.89 | +236 bearers (+2.8%) | Up 233 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 Aguiar 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 | #4,227 | #3,994 | 5.5% |
| Count | 8,390 | 8,626 | 2.8% |
| Per 100K | 2.84 | 2.89 | 1.6% |
Between the 2010 and 2020 Census, the number of Aguiar bearers went from 8,390 to 8,626 (+2.8% change). The surname moved up 233 positions in the national ranking, going from #4,227 to #3,994.
FAQ
Aguiar surname: questions and answers
How many people in the U.S. have the surname Aguiar?
Name Census estimates that about 9,892 living Americans carry the surname Aguiar. Using the current population baseline, that works out to roughly 1 in 34,650 residents.
How common is Aguiar?
Aguiar ranks #3,994 in the 2020 Census surname tables and is classified on this site as "Rare." The Census recorded the name at a frequency of 2.89 per 100,000 residents, which is about 3 people out of every 100,000.
How many people with this surname were counted in the Census?
The raw 2020 Census file counted 8,626 people with the surname Aguiar. That is different from the site's living-bearer estimate (9,892), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 2.89 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 2.89 per 100,000 means that if you picked a random group of 100,000 U.S. residents, you would expect about 3 of them to have the surname Aguiar.
Has Aguiar become more or less common over time?
Between 2010 and 2020, the surname Aguiar went from 8,390 recorded bearers to 8,626. That is an increase of 236 (+2.8%). In the national ranking it rose from #4,227 to #3,994.
What does the Census say about the background of Aguiar?
Among Census respondents with the surname Aguiar, the largest self-reported group is Hispanic at 47.8%. The next largest groups are White (46.8%) and Two or More Races (2.2%). 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?
Hispanic is the largest self-reported group for the surname Aguiar in the 2020 Census, accounting for 47.8% (4,119 people in the source table).
What is the full ancestry breakdown?
Aguiar appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are Hispanic (47.8%), White (46.8%), Two or More Races (2.2%). 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 Aguiar (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 Aguiar mean?
A Galician and Portuguese habitational surname referring to someone who lived near a field or open space. 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 Aguiar (2.89 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 last name Aguiar?
See how many people have the surname Aguiar on HowManyOfMe.org, our sister site built around that single question.