2000
#134,929
National surname rank
Recorded bearers 115
First available Census row
Per 100,000 0.04
Very Rare Last name
Fillius
A surname derived from the Latin word "filius" meaning "son".
According to the 2020 US Census Bureau surname tables, roughly 126 Americans carry the last name Fillius. That puts it at #149,446 in the national surname ranking, appearing at a frequency of 0.04 per 100,000 people (about 1 in 2,720,273 residents).
This page is the full Name Census profile for the Fillius 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
126
1 in 2,720,273
Census rank
#149,446
2020 decennial data
Per 100,000
0.0
Frequency rate
Recorded bearers
110
very rare in the US
Popularity narrative
The Census Bureau recorded 110 bearers of the surname Fillius in its 2020 decennial surname file. At a rate of 0.04 per 100,000 residents, it holds the 149446th position in the national surname ranking.
Among Census respondents with the surname Fillius, the largest self-reported group is White at 85.5%. The next largest groups are Hispanic (5.5%) and Two or More Races (5.5%).
Origin
Meaning and origin of Fillius
The surname Fillius originates from the Latin word "filius," meaning "son." This name likely arose as a descriptive surname in medieval times when hereditary surnames were becoming more common. It may have been used to distinguish the son of someone with the same given name or as a way to identify someone as the son of a particular individual or family.
Fillius is believed to have first emerged in regions of Europe where Latin was widely spoken or had a strong influence, such as Italy, France, and parts of Spain. The earliest recorded instances of the surname can be traced back to the 13th and 14th centuries in various Latin documents and records.
One notable early reference to the name Fillius can be found in the "Rationes Decimarum Italiae," a collection of records related to the collection of tithes in Italy during the late 13th century. This document mentions individuals with the surname Fillius residing in various Italian cities, including Rome and Florence.
In the 14th century, the surname Fillius appears in several French and Spanish records, suggesting its spread across different regions of Europe. For example, the "Livre des Bourgeois de Valenciennes" (Book of the Burghers of Valenciennes), dated around 1360, lists a certain Jehan Fillius among the citizens of the town.
Over the centuries, the surname Fillius has undergone various spelling variations, such as Fillius, Filius, Fillio, and Filio, reflecting regional linguistic differences and scribal variations.
Prominent individuals with the surname Fillius throughout history include:
1. Pietro Fillius (c. 1290-1356), an Italian jurist and legal scholar from Pisa, known for his commentaries on Roman law.
2. Jean Fillius (c. 1380-1446), a French cleric and professor of canon law at the University of Paris.
3. Bartolomé Fillius (c. 1520-1587), a Spanish theologian and philosopher who taught at the University of Salamanca.
4. Antonio Fillius (c. 1620-1690), an Italian painter and engraver from Naples known for his religious works.
5. Guilherme Fillius (1790-1865), a Portuguese writer and poet who contributed to the development of Romanticism in Portuguese literature.
While the surname Fillius is not as common today as it once was, it remains a part of many family histories and serves as a reminder of the rich linguistic and cultural heritage of Europe and the Latin-influenced regions where it originated.
Demographics
Ancestry and ethnicity for Fillius
Among Census respondents with the surname Fillius, the largest self-reported group is White at 85.5%. The next largest groups are Hispanic (5.5%) and Two or More Races (5.5%).
The bar chart below shows how Fillius 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 Fillius surname at the time of the 2020 Census, not any inherent property of the name itself.
- White85.5% · 94
- Hispanic or Latino5.5% · 6
- Two or more races5.5% · 6
- Black or African American3.6% · 4
Timeline
Historical Census data for Fillius
Fillius 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
#144,141
National surname rank
Recorded bearers 115
+0 bearers (+0.0%)
Per 100,000 0.04
Rank movement Down 9,212 places
2020
#149,446
National surname rank
Recorded bearers 110
-5 bearers (-4.3%)
Per 100,000 0.04
Rank movement Down 5,305 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #134,929 | 115 | 0.04 | First available Census row | First available Census row |
| 2010 | #144,141 | 115 | 0.04 | +0 bearers (+0.0%) | Down 9,212 places |
| 2020 | #149,446 | 110 | 0.04 | -5 bearers (-4.3%) | Down 5,305 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 Fillius 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 | #144,141 | #149,446 | -3.7% |
| Count | 115 | 110 | -4.3% |
| Per 100K | 0.04 | 0.04 | -8.0% |
Between the 2010 and 2020 Census, the number of Fillius bearers went from 115 to 110 (-4.3% change). The surname moved down 5,305 positions in the national ranking, going from #144,141 to #149,446.
FAQ
Fillius surname: questions and answers
How many people in the U.S. have the surname Fillius?
Name Census estimates that about 126 living Americans carry the surname Fillius. Using the current population baseline, that works out to roughly 1 in 2,720,273 residents.
How common is Fillius?
Fillius ranks #149,446 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 110 people with the surname Fillius. That is different from the site's living-bearer estimate (126), 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 Fillius.
Has Fillius become more or less common over time?
Between 2010 and 2020, the surname Fillius went from 115 recorded bearers to 110. That is a decrease of 5 (-4.3%). In the national ranking it fell from #144,141 to #149,446.
What does the Census say about the background of Fillius?
Among Census respondents with the surname Fillius, the largest self-reported group is White at 85.5%. The next largest groups are Hispanic (5.5%) and Two or More Races (5.5%). 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 Fillius in the 2020 Census, accounting for 85.5% (94 people in the source table).
What is the full ancestry breakdown?
Fillius appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (85.5%), Hispanic (5.5%), Two or More Races (5.5%). 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 Fillius (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 Fillius mean?
A surname derived from the Latin word "filius" meaning "son". 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 Fillius (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 Fillius?
For a quick modern estimate, our sister site HowManyOfMe.org answers that in one glance, with the living-bearer count front and centre.