2000
#120,330
National surname rank
Recorded bearers 133
First available Census row
Per 100,000 0.05
Very Rare Last name
Casilli
An Italian surname originating from the name of a town in Molise, Italy.
According to the 2020 US Census Bureau surname tables, roughly 173 Americans carry the last name Casilli. That puts it at #120,768 in the national surname ranking, appearing at a frequency of 0.05 per 100,000 people (about 1 in 1,981,239 residents).
This page is the full Name Census profile for the Casilli 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
173
1 in 1,981,239
Census rank
#120,768
2020 decennial data
Per 100,000
0.1
Frequency rate
Recorded bearers
151
very rare in the US
Popularity narrative
The Census Bureau recorded 151 bearers of the surname Casilli in its 2020 decennial surname file. At a rate of 0.05 per 100,000 residents, it holds the 120768th position in the national surname ranking.
Among Census respondents with the surname Casilli, the largest self-reported group is White at 94.0%. The next largest groups are Hispanic (5.3%) and Two or More Races (0.7%).
Origin
Meaning and origin of Casilli
The surname Casilli has its origins in Italy, specifically in the region of Campania. It is believed to have emerged during the medieval period, around the 11th or 12th century.
One theory suggests that the name Casilli is derived from the Latin word "casa," meaning house or dwelling. It may have been used to denote someone who lived in a particular house or settlement, or it could refer to the occupation of a builder or constructor of houses.
Another possible origin traces the name back to the Italian word "casale," which refers to a small village or hamlet. In this case, the name Casilli may have been associated with individuals who hailed from a specific casale or rural community.
Some of the earliest known references to the name Casilli can be found in historical documents and records from the Kingdom of Naples and the surrounding areas of Campania. For instance, there are mentions of individuals bearing the name in the "Codice Diplomatico Normanno," a collection of medieval charters and documents dating back to the Norman rule in southern Italy.
One notable figure in history with the surname Casilli was Pietro Casilli, a renowned painter from Naples who lived during the 16th century (circa 1500-1560). His works, which included religious paintings and frescoes, can still be found in various churches and museums in and around Naples.
Another individual of note was Girolamo Casilli, a 17th-century jurist and legal scholar from the town of Amalfi. He authored several treatises on civil and canon law, which were widely respected and influential during his time.
In the 18th century, there was Vincenzo Casilli, a prominent architect from the city of Salerno. He was responsible for designing several notable buildings and structures in and around the region, including churches and public works.
Moving into the 19th century, one can find references to Luigi Casilli, a renowned linguist and philologist from Naples. He made significant contributions to the study of Italian dialects and published several works on the subject.
Lastly, a more recent figure with the surname Casilli was Raffaele Casilli, an Italian politician and statesman who served as a member of the Italian Senate in the early 20th century (born in 1868, died in 1943).
While the surname Casilli is believed to have originated in the Campania region of Italy, over the centuries it has spread to other parts of the country and beyond, with individuals bearing this name making their mark in various fields and professions.
Demographics
Ancestry and ethnicity for Casilli
Among Census respondents with the surname Casilli, the largest self-reported group is White at 94.0%. The next largest groups are Hispanic (5.3%) and Two or More Races (0.7%).
The bar chart below shows how Casilli 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 Casilli surname at the time of the 2020 Census, not any inherent property of the name itself.
- White94.0% · 142
- Hispanic or Latino5.3% · 8
- Two or more races0.7% · 1
Timeline
Historical Census data for Casilli
Casilli 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
#108,734
National surname rank
Recorded bearers 163
+30 bearers (+22.6%)
Per 100,000 0.06
Rank movement Up 11,596 places
2020
#120,768
National surname rank
Recorded bearers 151
-12 bearers (-7.4%)
Per 100,000 0.05
Rank movement Down 12,034 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #120,330 | 133 | 0.05 | First available Census row | First available Census row |
| 2010 | #108,734 | 163 | 0.06 | +30 bearers (+22.6%) | Up 11,596 places |
| 2020 | #120,768 | 151 | 0.05 | -12 bearers (-7.4%) | Down 12,034 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 Casilli 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 | #108,734 | #120,768 | -11.1% |
| Count | 163 | 151 | -7.4% |
| Per 100K | 0.06 | 0.05 | -15.8% |
Between the 2010 and 2020 Census, the number of Casilli bearers went from 163 to 151 (-7.4% change). The surname moved down 12,034 positions in the national ranking, going from #108,734 to #120,768.
FAQ
Casilli surname: questions and answers
How many people in the U.S. have the surname Casilli?
Name Census estimates that about 173 living Americans carry the surname Casilli. Using the current population baseline, that works out to roughly 1 in 1,981,239 residents.
How common is Casilli?
Casilli ranks #120,768 in the 2020 Census surname tables and is classified on this site as "Very Rare." The Census recorded the name at a frequency of 0.05 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 151 people with the surname Casilli. That is different from the site's living-bearer estimate (173), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 0.05 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 0.05 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 Casilli.
Has Casilli become more or less common over time?
Between 2010 and 2020, the surname Casilli went from 163 recorded bearers to 151. That is a decrease of 12 (-7.4%). In the national ranking it fell from #108,734 to #120,768.
What does the Census say about the background of Casilli?
Among Census respondents with the surname Casilli, the largest self-reported group is White at 94.0%. The next largest groups are Hispanic (5.3%) and Two or More Races (0.7%). 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 Casilli in the 2020 Census, accounting for 94.0% (142 people in the source table).
What is the full ancestry breakdown?
Casilli appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (94.0%), Hispanic (5.3%), Two or More Races (0.7%). 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 Casilli (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 Casilli mean?
An Italian surname originating from the name of a town in Molise, Italy. 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 Casilli (0.05 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 Casilli?
Our sister site HowManyOfMe.org answers how common the surname Casilli is at a glance, with the living-bearer count up front.