Guillermo
/G-AH-IH-L-L-EH-R-M-AA/
Resolute protector, the Spanish form of William, from Germanic wil (will, resolve) joined to helm (helmet, protection). It names a guardian whose protecting strength is matched by an unbending will, and stands as the enduring Iberian form of that great medieval name.
Get Guillermo's full report — patron saint, feast day & a portrait — freeQuick — what every Christian parent asks about Guillermo:
How well does Guillermo fit your family?
This page tells you what Guillermo means. The app tells you whether it's right for your baby — scored against your family & your heritage, and your baby's birth details.
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Six signals — scored for your family & heritage, not in the abstract:
Meaning & origin
Yes — Guillermo is a Christian boy name of Spanish origin, meaning “Resolute protector, the Spanish form of William, from Germanic wil (will, resolve) joined to helm (helmet, protection). It names a guardian whose protecting strength is matched by an unbending will, and stands as the enduring Iberian form of that great medieval name.”.
Guillermo is a boy's name of Spanish origin, traditionally used in Christian families. The name means "Resolute protector, the Spanish form of William, from Germanic wil (will, resolve) joined to helm (helmet, protection). It names a guardian whose protecting strength is matched by an unbending will, and stands as the enduring Iberian form of that great medieval name." and belongs to the Courage cluster — names for children who will grow into bold, fearless hearts.
Common among Spanish, European, Latino, Mexican, Cuban, Argentine, Colombian, Chilean, Peruvian, Venezuelan, PuertoRican, Dominican families, Guillermo carries cultural weight that goes beyond its dictionary definition — it's a name with a story and a community.
The patron saint & feast day behind Guillermo
Many Christian names carry a patron saint and a feast day (name day) — a tradition of choosing a name for the saint a child is born near, or one the family holds dear. Guillermo lives in this tradition of meaning and heritage.
NameRoot connects the dots. See Guillermo's patron saint, its feast day, and whether it aligns with your baby's birth — alongside its full family score.
See Guillermo's saint & feast day →What does Guillermo's numerology say?
Numerology assigns each name a single-digit destiny number by summing its letter values. Different schools use different mappings — NameRoot computes both so you can see how Guillermo resonates in either tradition.
Guillermo's destiny number is 4 — but a number only matters in context. The app matches it to your family's own numbers for a real compatibility read. See Guillermo's full reading →
Does Guillermo go with your family's names?
Guillermo breaks into 9 sounds: /G-AH-IH-L-L-EH-R-M-AA/. The real test isn't how it sounds alone — it's how it sounds beside the names already in your family: yours, your partner's, and any brothers or sisters. NameRoot scores that harmony, so Guillermo sits naturally next to a Mum and Dad like Michael & Anna, or a big sister named Gianna — no awkward clashes, no two names that blur together. Hear Guillermo beside your family's names →
Nicknames
Common affectionate forms of Guillermo — useful for everyday family conversation, early childhood, or as standalone given names themselves.
Names similar to Guillermo
If Guillermo resonates with you, these names live in the same world — drawn from the same tradition, sharing the same meaning, or echoing a similar sound.
From the same tradition
Other Christian boy names, common in Spanish families
Sharing the same meaning
Other Christian boy names from the Courage cluster
Names that sound similar
Christian boy names that open with the same syllables as Guillermo
Explore more names
Keep exploring names like Guillermo — by tradition, by meaning, or by first letter.
Common questions about Guillermo
What does the name Guillermo mean?
Guillermo means "Resolute protector, the Spanish form of William, from Germanic wil (will, resolve) joined to helm (helmet, protection). It names a guardian whose protecting strength is matched by an unbending will, and stands as the enduring Iberian form of that great medieval name.." It is a boy name of Spanish origin, traditionally used in Christian families.
Is Guillermo a boy or girl name?
Guillermo is most commonly used as a boy name.
What is the origin of the name Guillermo?
Guillermo is of Spanish origin, used in Christian tradition, commonly among Spanish, European, Latino families.
Is Guillermo a Christian name?
Yes. Guillermo is a boy name traditionally used in Christian families, of Spanish origin.
What does Guillermo mean in Spanish?
Guillermo originates from Spanish, where it means "Resolute protector, the Spanish form of William, from Germanic wil (will, resolve) joined to helm (helmet, protection). It names a guardian whose protecting strength is matched by an unbending will, and stands as the enduring Iberian form of that great medieval name.."
What are common nicknames for Guillermo?
Common short forms of Guillermo include Guili, Guil.
What is the numerology of Guillermo?
Guillermo has a Pythagorean destiny number of 4 — stability and disciplined work.
See how Guillermo scores for your family
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