2000
#138,741
National surname rank
Recorded bearers 111
First available Census row
Per 100,000 0.04
Very Rare Last name
Mastrorocco
An occupational surname associated with a master builder or architect.
According to the 2020 US Census Bureau surname tables, roughly 127 Americans carry the last name Mastrorocco. That puts it at #148,665 in the national surname ranking, appearing at a frequency of 0.04 per 100,000 people (about 1 in 2,698,853 residents).
This page is the full Name Census profile for the Mastrorocco 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
127
1 in 2,698,853
Census rank
#148,665
2020 decennial data
Per 100,000
0.0
Frequency rate
Recorded bearers
111
very rare in the US
Popularity narrative
The Census Bureau recorded 111 bearers of the surname Mastrorocco in its 2020 decennial surname file. At a rate of 0.04 per 100,000 residents, it holds the 148665th position in the national surname ranking.
Among Census respondents with the surname Mastrorocco, the largest self-reported group is White at 100.0%.
Origin
Meaning and origin of Mastrorocco
The surname Mastrorocco has its origins in Italy, dating back to the 13th century. It is believed to have originated from the region of Campania, particularly in the areas around Naples and the Amalfi Coast. The name is derived from the Italian words "mastro" and "rocco," with "mastro" meaning "master" and "rocco" being a diminutive form of the name Rocco.
One of the earliest recorded instances of the surname Mastrorocco can be found in the "Codex Diplomaticus Cajetanus," a collection of historical documents from the region of Gaeta, dated around 1275. In this document, a certain "Petrus Mastrorocco" is mentioned as a landowner in the area.
During the Renaissance period, several notable individuals bore the surname Mastrorocco. One such figure was Girolamo Mastrorocco (1501-1574), a renowned architect and sculptor from Naples who contributed to the construction of several churches and palaces in the city.
In the 17th century, the name appears in the historical records of Amalfi, with the mention of a certain Gennaro Mastrorocco (1625-1690), a prominent merchant and ship-owner who played a significant role in the maritime trade of the region.
Another notable figure was Antonio Mastrorocco (1760-1832), a lawyer and judge from the town of Sorrento. He was widely respected for his legal expertise and served as a magistrate during the Napoleonic era.
Moving into the 19th century, the surname gained further prominence with the birth of Giuseppe Mastrorocco (1818-1891), a celebrated painter and art teacher from Naples. His works were highly regarded and can be found in various museums and galleries throughout Italy.
It is worth noting that the name Mastrorocco has also been associated with several geographical locations in Italy, such as the town of Mastrorocco in the province of Caserta and the Mastrorocco neighborhood in Naples, further reinforcing the historical roots of this surname.
Demographics
Ancestry and ethnicity for Mastrorocco
Among Census respondents with the surname Mastrorocco, the largest self-reported group is White at 100.0%.
The bar chart below shows how Mastrorocco 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 Mastrorocco surname at the time of the 2020 Census, not any inherent property of the name itself.
- White100.0% · 111
Timeline
Historical Census data for Mastrorocco
Mastrorocco 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
#133,863
National surname rank
Recorded bearers 126
+15 bearers (+13.5%)
Per 100,000 0.04
Rank movement Up 4,878 places
2020
#148,665
National surname rank
Recorded bearers 111
-15 bearers (-11.9%)
Per 100,000 0.04
Rank movement Down 14,802 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #138,741 | 111 | 0.04 | First available Census row | First available Census row |
| 2010 | #133,863 | 126 | 0.04 | +15 bearers (+13.5%) | Up 4,878 places |
| 2020 | #148,665 | 111 | 0.04 | -15 bearers (-11.9%) | Down 14,802 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 Mastrorocco 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 | #133,863 | #148,665 | -11.1% |
| Count | 126 | 111 | -11.9% |
| Per 100K | 0.04 | 0.04 | -7.2% |
Between the 2010 and 2020 Census, the number of Mastrorocco bearers went from 126 to 111 (-11.9% change). The surname moved down 14,802 positions in the national ranking, going from #133,863 to #148,665.
FAQ
Mastrorocco surname: questions and answers
How many people in the U.S. have the surname Mastrorocco?
Name Census estimates that about 127 living Americans carry the surname Mastrorocco. Using the current population baseline, that works out to roughly 1 in 2,698,853 residents.
How common is Mastrorocco?
Mastrorocco ranks #148,665 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 111 people with the surname Mastrorocco. That is different from the site's living-bearer estimate (127), 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 Mastrorocco.
Has Mastrorocco become more or less common over time?
Between 2010 and 2020, the surname Mastrorocco went from 126 recorded bearers to 111. That is a decrease of 15 (-11.9%). In the national ranking it fell from #133,863 to #148,665.
What does the Census say about the background of Mastrorocco?
Among Census respondents with the surname Mastrorocco, the largest self-reported group is White at 100.0%. 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 Mastrorocco in the 2020 Census, accounting for 100.0% (111 people in the source table).
What is the full ancestry breakdown?
Mastrorocco appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (100.0%). 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 Mastrorocco (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 Mastrorocco mean?
An occupational surname associated with a master builder or architect. 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 Mastrorocco (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 Mastrorocco?
HowManyOfMe.org, our sister site, answers that with the living-bearer count in one glance.