Masculine dossier · first seen 1885
Guillermo
Stable
Cross-generational persistence
Peak era
1998
Peak births
693
Current vitality
Fragile
Peak generation
Gen Z
Quick answers about Guillermo
How many people are named Guillermo?
An estimated 27,823 living Americans are named Guillermo.
How rare is Guillermo?
Guillermo is uncommon among babies today, with 264 boys receiving the name in 2025, down 61.9% from its 1998 peak.
How old is the typical Guillermo?
The median age of a living American named Guillermo is approximately 31 years, with most bearers falling between 19 and 44 years old.
Is Guillermo still popular?
Yes. Guillermo is holding steady, with 264 births in 2025 and a consistent recent baseline.
Where is Guillermo most common?
Guillermo has its strongest geographic signal in New Mexico, where it appears 26.5× more often than the national baseline.
1885Peak 19982025
Peak year
1998
Decline from peak
61.9%
2025
264
All-time
32,074
Where it lives now
Guillermo is most concentrated in Arizona — about 19.1× the national rate in the 1930s.
States where Guillermo is given more often than the national average — its present-day heartland.