2000
#13,554
National surname rank
Recorded bearers 2,055
First available Census row
Per 100,000 0.76
Rare Last name
Castaldo
An Italian occupational surname referring to the keeper or governor of a castle or fortress.
According to the 2020 US Census Bureau surname tables, roughly 2,073 Americans carry the last name Castaldo. That puts it at #15,568 in the national surname ranking, appearing at a frequency of 0.60 per 100,000 people (about 1 in 165,342 residents).
This page is the full Name Census profile for the Castaldo 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
2.1K
1 in 165,342
Census rank
#15,568
2020 decennial data
Per 100,000
0.6
Frequency rate
Recorded bearers
1.8K
rare in the US
Popularity narrative
The Census Bureau recorded 1,808 bearers of the surname Castaldo in its 2020 decennial surname file. At a rate of 0.60 per 100,000 residents, it holds the 15568th position in the national surname ranking.
Among Census respondents with the surname Castaldo, the largest self-reported group is White at 90.5%. The next largest groups are Hispanic (7.6%) and Two or More Races (0.9%).
Origin
Meaning and origin of Castaldo
The surname Castaldo originated in Italy, with its earliest known origins traced back to the medieval period. It is believed to have derived from the Italian word "castaldo," which referred to a steward or overseer of a castle or estate. This occupation-based surname suggests that the earliest bearers of the name were likely employed in this role, managing the affairs of a noble household or landowner.
One of the earliest recorded instances of the Castaldo surname can be found in the historical records of the city of Naples, where a family by this name held prominent positions in the 13th century. Notably, Giovanni Castaldo, born around 1250, served as a trusted advisor and diplomat to the Angevin rulers of the Kingdom of Naples.
In the 14th century, the Castaldo name appeared in the annals of the Republic of Genoa, where a branch of the family had established itself. Several members of the Genoese Castaldo family were influential merchants and bankers, contributing to the city's flourishing maritime trade.
During the Renaissance period, the Castaldo surname gained further prominence with the birth of Giovanni Battista Castaldo (1493-1563), an Italian military commander and diplomat who served under the Holy Roman Emperor Charles V. He played a crucial role in the Italian Wars and the conflicts against the Ottoman Empire, earning a reputation as a skilled strategist and negotiator.
Another notable figure bearing the Castaldo name was Basilio Castaldo (1624-1656), an Italian painter and engraver from Naples. His works, which included religious and mythological scenes, were celebrated for their attention to detail and mastery of chiaroscuro techniques.
In the 18th century, the Castaldo family produced another distinguished individual, Gennaro Castaldo (1738-1810), a Neapolitan lawyer and statesman. He served as a high-ranking official in the Kingdom of Naples during the turbulent years of the Napoleonic era, navigating the complex political landscape with skill and diplomacy.
While the Castaldo surname has its roots in Italy, it has since spread to other parts of the world through migration and intermarriage. However, its origins can be traced back to the medieval period, when the name first emerged as an occupational designation for those charged with overseeing castles and estates.
Demographics
Ancestry and ethnicity for Castaldo
Among Census respondents with the surname Castaldo, the largest self-reported group is White at 90.5%. The next largest groups are Hispanic (7.6%) and Two or More Races (0.9%).
The bar chart below shows how Castaldo 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 Castaldo surname at the time of the 2020 Census, not any inherent property of the name itself.
- White90.5% · 1,636
- Hispanic or Latino7.6% · 137
- Two or more races0.9% · 17
- Asian and Pacific Islander0.7% · 12
- Black or African American0.3% · 6
Timeline
Historical Census data for Castaldo
Castaldo 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
#13,627
National surname rank
Recorded bearers 2,222
+167 bearers (+8.1%)
Per 100,000 0.75
Rank movement Down 73 places
2020
#15,568
National surname rank
Recorded bearers 1,808
-414 bearers (-18.6%)
Per 100,000 0.60
Rank movement Down 1,941 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #13,554 | 2,055 | 0.76 | First available Census row | First available Census row |
| 2010 | #13,627 | 2,222 | 0.75 | +167 bearers (+8.1%) | Down 73 places |
| 2020 | #15,568 | 1,808 | 0.60 | -414 bearers (-18.6%) | Down 1,941 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 Castaldo 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 | #13,627 | #15,568 | -14.2% |
| Count | 2,222 | 1,808 | -18.6% |
| Per 100K | 0.75 | 0.60 | -19.3% |
Between the 2010 and 2020 Census, the number of Castaldo bearers went from 2,222 to 1,808 (-18.6% change). The surname moved down 1,941 positions in the national ranking, going from #13,627 to #15,568.
FAQ
Castaldo surname: questions and answers
How many people in the U.S. have the surname Castaldo?
Name Census estimates that about 2,073 living Americans carry the surname Castaldo. Using the current population baseline, that works out to roughly 1 in 165,342 residents.
How common is Castaldo?
Castaldo ranks #15,568 in the 2020 Census surname tables and is classified on this site as "Rare." The Census recorded the name at a frequency of 0.60 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 1,808 people with the surname Castaldo. That is different from the site's living-bearer estimate (2,073), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 0.6 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 0.60 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 Castaldo.
Has Castaldo become more or less common over time?
Between 2010 and 2020, the surname Castaldo went from 2,222 recorded bearers to 1,808. That is a decrease of 414 (-18.6%). In the national ranking it fell from #13,627 to #15,568.
What does the Census say about the background of Castaldo?
Among Census respondents with the surname Castaldo, the largest self-reported group is White at 90.5%. The next largest groups are Hispanic (7.6%) and Two or More Races (0.9%). 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 Castaldo in the 2020 Census, accounting for 90.5% (1,636 people in the source table).
What is the full ancestry breakdown?
Castaldo appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (90.5%), Hispanic (7.6%), Two or More Races (0.9%). 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 Castaldo (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 Castaldo mean?
An Italian occupational surname referring to the keeper or governor of a castle or fortress. 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 Castaldo (0.60 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 are called Castaldo?
Want to know how many people are called Castaldo? HowManyOfMe.org, our sister site, puts the living-bearer count front and centre.