2000
#8,872
National surname rank
Recorded bearers 3,394
First available Census row
Per 100,000 1.26
Rare Last name
Demaio
An Italian occupational surname referring to someone who worked as a steward or majordomo.
According to the 2020 US Census Bureau surname tables, roughly 3,798 Americans carry the last name Demaio. That puts it at #9,414 in the national surname ranking, appearing at a frequency of 1.11 per 100,000 people (about 1 in 90,246 residents).
This page is the full Name Census profile for the Demaio 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
3.8K
1 in 90,246
Census rank
#9,414
2020 decennial data
Per 100,000
1.1
Frequency rate
Recorded bearers
3.3K
rare in the US
Popularity narrative
The Census Bureau recorded 3,312 bearers of the surname Demaio in its 2020 decennial surname file. At a rate of 1.11 per 100,000 residents, it holds the 9414th position in the national surname ranking.
Among Census respondents with the surname Demaio, the largest self-reported group is White at 91.8%. The next largest groups are Hispanic (5.0%) and Two or More Races (1.9%).
Origin
Meaning and origin of Demaio
The surname DEMAIO originated in Italy, with its roots tracing back to the 14th century. The name is believed to have derived from the Italian word "maggio," meaning the month of May. It's possible that the surname was initially given to someone born or baptized during that month.
One of the earliest recorded instances of the DEMAIO surname can be found in the Libro d'Oro della Nobiltà Italiana, a register of Italian nobility published in the late 16th century. In this document, the name appears as "DeMaio," indicating a family of noble lineage.
The DEMAIO surname has been associated with various regions in Italy, particularly in the southern regions of Campania and Calabria. Some historical records also suggest the presence of families bearing this name in Sicily.
In the 15th century, a notable figure with the DEMAIO surname was Giovanni DeMaio, a renowned architect from Naples. He is credited with designing several churches and palaces in the city, including the Church of San Giovanni a Carbonara.
Another notable individual was Pietro DeMaio, a 16th-century Neapolitan philosopher and scholar. He authored several works on metaphysics and logic, contributing significantly to the intellectual discourse of his time.
During the 17th century, the DEMAIO family gained prominence in the town of Sorrento, located in the Campania region. A notable member was Giacomo DeMaio, a successful merchant and landowner who played a significant role in the local community.
In the 18th century, the DEMAIO surname appeared in various records from the Kingdom of Naples. One prominent figure was Antonio DeMaio, a military officer who served under the Bourbon dynasty.
In the 19th century, several individuals with the DEMAIO surname achieved recognition in various fields. Giuseppe DeMaio was a celebrated painter from Naples, known for his landscapes and still-life works. Vincenzo DeMaio, on the other hand, was a renowned composer and music theorist who contributed significantly to the development of Neapolitan music.
Demographics
Ancestry and ethnicity for Demaio
Among Census respondents with the surname Demaio, the largest self-reported group is White at 91.8%. The next largest groups are Hispanic (5.0%) and Two or More Races (1.9%).
The bar chart below shows how Demaio 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 Demaio surname at the time of the 2020 Census, not any inherent property of the name itself.
- White91.8% · 3,041
- Hispanic or Latino5.0% · 167
- Two or more races1.9% · 62
- Black or African American0.8% · 28
- Asian and Pacific Islander0.4% · 13
- American Indian and Alaska Native0.0% · 1
Timeline
Historical Census data for Demaio
Demaio 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
#9,208
National surname rank
Recorded bearers 3,542
+148 bearers (+4.4%)
Per 100,000 1.20
Rank movement Down 336 places
2020
#9,414
National surname rank
Recorded bearers 3,312
-230 bearers (-6.5%)
Per 100,000 1.11
Rank movement Down 206 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #8,872 | 3,394 | 1.26 | First available Census row | First available Census row |
| 2010 | #9,208 | 3,542 | 1.20 | +148 bearers (+4.4%) | Down 336 places |
| 2020 | #9,414 | 3,312 | 1.11 | -230 bearers (-6.5%) | Down 206 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 Demaio 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 | #9,208 | #9,414 | -2.2% |
| Count | 3,542 | 3,312 | -6.5% |
| Per 100K | 1.20 | 1.11 | -7.7% |
Between the 2010 and 2020 Census, the number of Demaio bearers went from 3,542 to 3,312 (-6.5% change). The surname moved down 206 positions in the national ranking, going from #9,208 to #9,414.
FAQ
Demaio surname: questions and answers
How many people in the U.S. have the surname Demaio?
Name Census estimates that about 3,798 living Americans carry the surname Demaio. Using the current population baseline, that works out to roughly 1 in 90,246 residents.
How common is Demaio?
Demaio ranks #9,414 in the 2020 Census surname tables and is classified on this site as "Rare." The Census recorded the name at a frequency of 1.11 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 3,312 people with the surname Demaio. That is different from the site's living-bearer estimate (3,798), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 1.11 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 1.11 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 Demaio.
Has Demaio become more or less common over time?
Between 2010 and 2020, the surname Demaio went from 3,542 recorded bearers to 3,312. That is a decrease of 230 (-6.5%). In the national ranking it fell from #9,208 to #9,414.
What does the Census say about the background of Demaio?
Among Census respondents with the surname Demaio, the largest self-reported group is White at 91.8%. The next largest groups are Hispanic (5.0%) and Two or More Races (1.9%). 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?
White is the largest self-reported group for the surname Demaio in the 2020 Census, accounting for 91.8% (3,041 people in the source table).
What is the full ancestry breakdown?
Demaio appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (91.8%), Hispanic (5.0%), Two or More Races (1.9%). 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 Demaio (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 Demaio mean?
An Italian occupational surname referring to someone who worked as a steward or majordomo. 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 Demaio (1.11 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 Demaio?
For a quick modern take, check how many people have the surname Demaio on our sister site HowManyOfMe.org.