2000
#138,741
National surname rank
Recorded bearers 111
First available Census row
Per 100,000 0.04
Very Rare Last name
Guglielmini
An Italian surname derived from the personal name Guglielmo, meaning "ardent protector."
According to the 2020 US Census Bureau surname tables, roughly 120 Americans carry the last name Guglielmini. That puts it at #152,989 in the national surname ranking, appearing at a frequency of 0.04 per 100,000 people (about 1 in 2,856,286 residents).
This page is the full Name Census profile for the Guglielmini 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
120
1 in 2,856,286
Census rank
#152,989
2020 decennial data
Per 100,000
0.0
Frequency rate
Recorded bearers
105
very rare in the US
Popularity narrative
The Census Bureau recorded 105 bearers of the surname Guglielmini in its 2020 decennial surname file. At a rate of 0.04 per 100,000 residents, it holds the 152989th position in the national surname ranking.
Among Census respondents with the surname Guglielmini, the largest self-reported group is White at 81.0%. The next largest groups are Hispanic (7.6%) and Black (5.7%).
Origin
Meaning and origin of Guglielmini
The surname Guglielmini originates from Italy, with its earliest roots dating back to the medieval period. It is believed to be a patronymic name derived from the Italian personal name Guglielmo, which is the Italian equivalent of the Germanic name Wilhelm, meaning "resolute protector."
Guglielmini is a diminutive form of the name, indicating a familial connection or descent from someone named Guglielmo. The name was particularly prevalent in the regions of Emilia-Romagna and Tuscany, where it was associated with noble families and scholars.
One of the earliest recorded instances of the name Guglielmini can be found in the 14th-century "Libro di Montaperti," a chronicle of the Battle of Montaperti fought between the Guelphs and Ghibellines in 1260. The document mentions a certain Guglielmino, who was likely a member of the Ghibelline faction.
In the 15th century, the name gained prominence with the birth of Domenico Guglielmini (1655-1710), a renowned Italian mathematician, physician, and naturalist. He made significant contributions to the study of hydrostatics and was appointed as the first professor of mathematics at the University of Bologna.
Another notable figure was Giambattista Guglielmini (1763-1817), an Italian architect and engineer who designed several important buildings in Rome, including the Palazzo del Quirinale and the Basilica of St. Paul Outside the Walls.
The name Guglielmini also appears in historical records from the 16th and 17th centuries, often associated with noble families in cities like Florence and Bologna. For instance, Vincenzo Guglielmini (1607-1678) was a prominent Florentine statesman and diplomat who served as the ambassador to France and the Holy Roman Empire.
In the 19th century, Giuseppe Guglielmini (1834-1910) was an Italian botanist and agronomist who made significant contributions to the study of plant diseases and their treatment. He served as the director of the Royal School of Pomology and Viticulture in Florence.
Throughout its history, the surname Guglielmini has been associated with scholars, artists, and influential figures, reflecting its noble origins and the esteemed status of those who bore this name in Italian society.
Demographics
Ancestry and ethnicity for Guglielmini
Among Census respondents with the surname Guglielmini, the largest self-reported group is White at 81.0%. The next largest groups are Hispanic (7.6%) and Black (5.7%).
The bar chart below shows how Guglielmini 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 Guglielmini surname at the time of the 2020 Census, not any inherent property of the name itself.
- White81.0% · 85
- Hispanic or Latino7.6% · 8
- Black or African American5.7% · 6
- Two or more races5.7% · 6
Timeline
Historical Census data for Guglielmini
Guglielmini 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
#148,347
National surname rank
Recorded bearers 111
+0 bearers (+0.0%)
Per 100,000 0.04
Rank movement Down 9,606 places
2020
#152,989
National surname rank
Recorded bearers 105
-6 bearers (-5.4%)
Per 100,000 0.04
Rank movement Down 4,642 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 | #148,347 | 111 | 0.04 | +0 bearers (+0.0%) | Down 9,606 places |
| 2020 | #152,989 | 105 | 0.04 | -6 bearers (-5.4%) | Down 4,642 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 Guglielmini 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 | #148,347 | #152,989 | -3.1% |
| Count | 111 | 105 | -5.4% |
| Per 100K | 0.04 | 0.04 | -12.2% |
Between the 2010 and 2020 Census, the number of Guglielmini bearers went from 111 to 105 (-5.4% change). The surname moved down 4,642 positions in the national ranking, going from #148,347 to #152,989.
FAQ
Guglielmini surname: questions and answers
How many people in the U.S. have the surname Guglielmini?
Name Census estimates that about 120 living Americans carry the surname Guglielmini. Using the current population baseline, that works out to roughly 1 in 2,856,286 residents.
How common is Guglielmini?
Guglielmini ranks #152,989 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 105 people with the surname Guglielmini. That is different from the site's living-bearer estimate (120), 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 Guglielmini.
Has Guglielmini become more or less common over time?
Between 2010 and 2020, the surname Guglielmini went from 111 recorded bearers to 105. That is a decrease of 6 (-5.4%). In the national ranking it fell from #148,347 to #152,989.
What does the Census say about the background of Guglielmini?
Among Census respondents with the surname Guglielmini, the largest self-reported group is White at 81.0%. The next largest groups are Hispanic (7.6%) and Black (5.7%). 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 Guglielmini in the 2020 Census, accounting for 81.0% (85 people in the source table).
What is the full ancestry breakdown?
Guglielmini appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (81.0%), Hispanic (7.6%), Black (5.7%). 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 Guglielmini (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 Guglielmini mean?
An Italian surname derived from the personal name Guglielmo, meaning "ardent protector." 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 Guglielmini (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 Guglielmini?
For a quick modern estimate, our sister site HowManyOfMe.org answers that in one glance, with the living-bearer count front and centre.