Guillermo
- Pronunciation
- [Gui-ller-mo]
- Gender
- Male
- Meaning
- Variant Of William Resolute Protector.
- Origin
- Spanish
About the Name Guillermo
Guillermo is the Spanish form of William, a name built on two ancient Germanic elements: wil, meaning "will" or "desire," and helm, meaning "helmet" or "protection." The combined sense — resolute protector — traveled from the Germanic tribes into Norman French as Guillaume and into English as William, while the Iberian Peninsula developed its own distinct form: Guillermo. Pronounced with the distinctive ll of Castilian Spanish, the name carries centuries of royal and literary use across the Spanish-speaking world, from Castilian court records to Latin American literature.
A notable bearer of this name is Guillermo Endara, a Panamanian lawyer who became president of Panama under the highly unusual circumstance of being sworn in on a United States military base on the eve of the December 1989 invasion that removed General Manuel Noriega from power. His presidency marked a pivotal transition in Panamanian history.
Guillermo first entered the US Social Security top-1000 in 2000, debuting at its peak rank of #392 — a strong initial showing that reflected the expanding Latino population in the United States. Since then the name has settled into the mid-to-lower reaches of the chart, sitting at #832 in 2024 with 297 boys receiving the name that year. Altogether more than 11,000 boys have been named Guillermo within the SSA top-1000 era. For families seeking an authentically Spanish given name with Old World weight and an unmistakably warm sound, Guillermo remains a compelling choice.
Source: U.S. Social Security Administration name data, 1880–2024 (methodology). By Marvin Tang.
Quick Facts About Guillermo
US Popularity History (2000–2025)
Annual US births named Guillermo by gender, from US Social Security Administration records. Peak year: 2000 with 651 boys named Guillermo (boy rank #392 that year).
Where it stands today: in 2025, ranked #902 for boys (264 US births). That's 510 places below its 2000 peak.
Source: US Social Security Administration. Limitations: US birth-certificate data only; names appearing fewer than 5 times in a given year are suppressed for privacy; spelling variants are counted separately. For names that ranked outside the US top 100 before year 2000, only the years they reached the top 100 are shown — the chart may have gaps for less-popular historical names.
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Where in the US Is Guillermo Most Popular?
Average boy-name rank within each state across 2016–2025 SSA records. A lower number means the name appears closer to the top of that state's boys-name rankings — a per-capita measure that isn't biased toward large states. For Guillermo the strongest states are New Mexico, Nevada, Arizona.
Strongest boys-name states
| # | State | Avg rank | Births |
|---|---|---|---|
| 1 | New Mexico | #380 | 16 |
| 2 | Nevada | #425 | 29 |
| 3 | Arizona | #431 | 156 |
| 4 | Texas | #434 | 700 |
| 5 | California | #454 | 675 |
| 6 | Colorado | #741 | 25 |
| 7 | Illinois | #756 | 97 |
| 8 | Florida | #778 | 152 |
| 9 | Washington | #805 | 51 |
| 10 | Georgia | #969 | 36 |
Weakest boys-name states
| # | State | Avg rank | Births |
|---|---|---|---|
| 1 | North Carolina | #1,000 | 30 |
| 2 | Georgia | #969 | 36 |
| 3 | Washington | #805 | 51 |
| 4 | Florida | #778 | 152 |
| 5 | Illinois | #756 | 97 |
| 6 | Colorado | #741 | 25 |
| 7 | California | #454 | 675 |
| 8 | Texas | #434 | 700 |
| 9 | Arizona | #431 | 156 |
| 10 | Nevada | #425 | 29 |
Source: SSA state-level baby-name dataset 2016–2025. States with fewer than 3 years of data for Guillermo in this window are excluded. Births < 5 in a given state-year are suppressed by SSA for privacy.
Famous People Named Guillermo
1 notable figure from history and culture who share the name Guillermo.
- Guillermo Endara was the President of Panama who was renowned for his efforts to establish democracy in the country.
Looking for names like Guillermo?
A dedicated page with 60+ related names — spelling variants, rhymes, alliterations, same-origin matches, and shared meaning concepts — lives at its own URL so each kind of similarity gets a deeper treatment than fits here.
Compare Guillermo to Other Popular Names
Side-by-side popularity charts and crossover years for Guillermo against today's most popular boys-name peers (top 8 by US births in the last 10 years of SSA records).
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