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, and state-by-state birth registrations. 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: 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.
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.
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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