How Many People Are Named Guillermo?
An estimated 28,333 people in the United States have the first name Guillermo. It is almost exclusively a male name. The average bearer is 34 years old, and Guillermo peaked in popularity in 1998 with 693 births that year.
Below you will find a full statistical profile of Guillermo as a first name in the United States, including gender data, a year-by-year popularity timeline going back to 1880, a decade breakdown, state-by-state birth registrations, and, when available, a 2020 Census snapshot showing who had the name at that point in time. You can also check how many people share the full name Guillermo paired with any surname.
Key Insights
- While Guillermo is overwhelmingly male, 74 female births have been registered with this name since 1880.
Estimated Living Americans
28,333
About 1 in 12,097 people in the U.S.
Rarity
Uncommon
Predicted Gender
Male
99.8% confidence
Average Age
34
years old
Peak Year
1998
693 births
Total Registered
31,881
since 1880
Gender Distribution for Guillermo
Guillermo is almost exclusively a male name. Out of 31,881 total births registered, 99.8% were male.
Guillermo as a male name
Ranked #832 in 2024
297 male births in 2024
Peak: 1998 (693 births)
Guillermo as a female name
Ranked #18,116 in 2006
5 female births in 2006
Peak: 1991 (8 births)
Guillermo in the 2020 Census
The 2020 Census recorded 61,844 people with the first name Guillermo, which placed it at #794 in the published first-name tables. This is a snapshot of people who already had the name in 2020. The estimated living count elsewhere on this page is different: it is a current estimate built from SSA birth records and age-based survival rates, so the two figures are not expected to match exactly.
Read this section as a snapshot of people who already had the name in 2020. The SSA charts elsewhere on this page are still the better way to see how the name rose, fell, or shifted across generations.
Gender in the 2020 Census
In the 2020 Census, Guillermo was recorded as predominantly male. Out of 61,844 people with this name in that snapshot, 99.8% were male and 0.2% were female. That is very close to the long-run birth pattern in SSA records, where the name is male 99.8% of the time.
Census Count
61,844
people with this name
Census Rank
#794
among Census first names
Frequency Rate
20.48
per 100,000 people
Recorded Race and Hispanic Origin in the 2020 Census
In the 2020 Census, the first name Guillermo was most commonly recorded among people who identified as Hispanic (96.79%). The next largest recorded groups were White (1.44%) and Asian and Pacific Islander (1.30%).
These percentages describe the people who had the first name Guillermo in the 2020 Census. They do not tell you the deeper meaning or origin of the name itself.
2020 Census demographic breakdown
Each row shows a recorded Census category for people with the first name Guillermo.
| Group | Share | Count |
|---|---|---|
| Hispanic | 96.79% | 59,854 |
| White | 1.44% | 893 |
| Asian and Pacific Islander | 1.30% | 805 |
| Black | 0.25% | 154 |
| Two or More Races | 0.11% | 69 |
| American Indian and Alaska Native | 0.11% | 65 |
The Census published separate sex and race/origin tables for first names, so their total counts can differ slightly for the same name. That is why the race section focuses on the demographic mix rather than repeating a second headline count.
Guillermo: Popularity Over Time
SSA records for Guillermo span from the 1880s to the 2020s, covering 15 decades of naming data. The most popular decade for this name was the 1990s, when 6,496 babies were registered. Guillermo has declined significantly from its peak in the 1990s. Recent registrations are a fraction of what they were at the name's height.
Guillermo by Decade
How has Guillermo tracked across different eras? The table below groups all SSA birth registrations into 10-year periods, with separate male and female counts. The colored bar shows each decade's share relative to the peak.
Guillermo by State
Birth registrations for Guillermo span all 35 states and territories in the SSA database. The highest counts are in California, Texas, Arizona. The lowest are in Idaho, Iowa, Alabama. On average, about 822 Guillermos were registered per state.
Guillermo + Last Name Combinations
How many people share a full name with Guillermo as the first name? Click a combination below to see the estimate, or search any pairing.
Names Similar to Guillermo
Other first names starting with G with a similar number of bearers.
Guillermo: Questions and Answers
How many people in the U.S. are named Guillermo?
We estimate approximately 28,333 people named Guillermo are alive in the United States today. This is based on SSA birth records from 1880 to 2024, adjusted for mortality using CDC life tables. About 1 in 12,097 Americans share this first name.
Is Guillermo a common name?
Guillermo is classified as "Uncommon" and is more popular than 98.8% of all first names in the SSA database. A total of 31,881 births have been registered with this name since 1880.
When was Guillermo most popular?
Guillermo reached peak popularity in 1998, when 693 babies were given this name. The average age of a living person named Guillermo is approximately 34 years old, reflecting when the name was most commonly given.
How common was Guillermo in the 2020 Census?
The 2020 Census recorded 61,844 people with the first name Guillermo. That placed it at #794 in the published Census first-name tables, or 20.48 people per 100,000.
Why is the Census count different from the living estimate?
Because they measure different things. The Census number is a count of people with the name in 2020. The living estimate is a current model based on SSA birth records and survival rates, so it aims to estimate how many people with the name are alive now.
What does the SSA popularity chart show?
The popularity chart tracks birth registrations, not people currently alive. It shows how often Guillermo was given to babies from 1880 through 2024, which is why it is the best tool on the page for seeing long-run naming trends.
What does the Census say about the gender split for Guillermo?
In the 2020 Census snapshot, Guillermo was recorded as predominantly male. The published split was 99.8% male and 0.2% female.
What does the Census say about the background of people named Guillermo?
In the 2020 Census, the first name Guillermo was most commonly recorded among people who identified as Hispanic (96.79%). The next largest recorded groups were White (1.44%) and Asian and Pacific Islander (1.30%). These percentages describe the people who had the name in the 2020 Census, not the deeper meaning or origin of the name itself.
Why can the Census sex total and race total differ slightly?
The Census published separate first-name tables for sex and for race and Hispanic origin. Those totals can differ slightly for the same name, so the page uses them as two related snapshots rather than treating them as perfectly interchangeable counts.
Does every first name have Census demographic data?
No. The public Census first-name tables only include names that met the Bureau's publication rules. That means some names on this site will have SSA history but no published Census demographic snapshot.
Is Guillermo a male name?
Guillermo is predominantly male. 99.8% of people with this name are male. See the gender breakdown above for full details.
Why can Guillermo have a lot of living bearers even if it is not trendy now?
Because a name can build up a large population over many decades. Guillermo peaked in 1998, and the average living bearer is about 34 years old, so a name can still have millions of living bearers even after it stops feeling current for newborns.
How many Guillermo Smiths are there?
To find how many people share a specific full name, we combine first name and surname frequencies. Try: Guillermo Smith, Guillermo Johnson, Guillermo Williams. You can also search any combination on our homepage.
Where does this data come from?
Our estimates use Social Security Administration birth records (1880 to 2024), adjusted for survival using CDC 2023 life tables broken down by sex. The U.S. population figure (342,754,338) is from the Census Bureau's July 2025 estimate. Full methodology.
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