Guillermo

boyOld GermanChristian

Guillermo is a Christian boy name of Old German, via Spanish origin, meaning “Resolute protector”.

MeaningResolute protector
GenderBoy
OriginOld German, via Spanish
Pronunciationgee-YEHR-moh
TraditionChristian, Modern & Classic
Used inSpain, Mexico, Argentina, Colombia

Meaning and origin of Guillermo

Guillermo is the Spanish form of William, from the Germanic elements wil, 'will, desire', and helm, 'helmet, protection'. The name became enormously popular after William the Conqueror and spread through every European language. Well-known Spanish-speaking bearers include the filmmaker Guillermo del Toro. Common nicknames are Memo in Mexico and Guille in Spain and Argentina. The name has been in Spanish use since the Middle Ages.

Is Guillermo a Christian name?

Guillermo is not a biblical name but has long been used in Catholic families, and several medieval saints called William are honoured in the Church.

How popular is Guillermo?

A classic, widely recognised name throughout the Spanish-speaking world.

Gifts with the name Guillermo

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Spellings and variants of Guillermo

WilliamGuillaumeWilhelmGuglielmoWillem

Names similar to Guillermo

More Christian boy names

Frequently asked questions

What does the name Guillermo mean?

Guillermo means 'Resolute protector'. It is of Old German, via Spanish origin.

Is Guillermo a Christian name?

Guillermo is not a biblical name but has long been used in Catholic families, and several medieval saints called William are honoured in the Church.

How do you pronounce Guillermo?

Guillermo is pronounced gee-YEHR-moh.

Is Guillermo a boy or girl name?

Guillermo is usually a boy name.

Updated October 2026. Spotted a mistake? Tell us.