Guillermo

Guillermo is the Spanish form of William, from a Germanic name combining will or desire with a word for a helmet or protection. The conventional interpretation reflects those older elements rather than a phrase originally spoken in Spanish. Guillermo belongs to the same international family as William, Wilhelm, and Guillaume, with its own established language form.

Guille and Memo are familiar nickname possibilities, offering quite different sounds from the full name. English readers may need help with the double l, whose pronunciation also varies across Spanish-speaking regions. Parents honoring a William can use Guillermo to maintain the family connection while choosing a name that fits a Spanish-speaking household or heritage.