Guillermo

What Guillermo means

Spanish form of William, meaning “will + helmet”

a male given name, equivalent to English William || From Middle English William, from Anglo-Norman Willame, from Old High German Willahelm, from Proto-Germanic *Wiljahelmaz (> Latin Gulielmus), from Proto-Germanic *wiljô (“will”) + *helmaz (“helmet”), ultimately from the Proto-Indo-European

Source: Wiktionary, “Guillermo” (revision 93487204) and “William” (revision 94595525), CC BY-SA 4.0. Quoted from the etymology; we don’t write our own.

How popular is Guillermo?

US: Falling: down from #661 in 2015.

Biggest US share so far: 1996, when 692 boys got the name (#352 that year). First in the US records in 1885.

How common

• About 1 in 6,470 baby boys in the US in 2025

“1 in N” divides by all listed births for that sex. The US list leaves out names given to fewer than 5 babies, and the UK lists leave out names given to 2 or fewer, so the real figure is a little rarer than shown.

Where in the US

Most popular in AZ (0.52 per 1,000 boys), NV (0.44 per 1,000 boys), TX (0.37 per 1,000 boys) in 2025.

SSA state data, 2025. Share of all listed boys born in each state.

US vs UK

Guillermo is #901 in the US. It is not in the England & Wales list for 2025.

Same sex as this page (boys). SSA (US), ONS (England and Wales), NRS (Scotland).

Boy or girl?

In 2025, 99.9+% of US babies named Guillermo were boys.

Counts below the publishing threshold (US 5, UK 3) are not included.

If you like Guillermo

Boys

• Jose#95Same root as Joseph, meaning “(God) shall add”^*
• Juan#159Spanish, meaning “Yahweh is gracious”^*
• Antonio#176Same root as Anthony, meaning “flower”^*
• Alex#232Short form of Alexandra, meaning “to defend + man”^*
• Nicholas#112“victory + people”^*
• Tyler#219“tiler”^*

For a sister

• Jasmine#206Editor’s note Down from #110 in 2015 to #206 in 2025 in the US
• Brianna#222Editor’s note Cooling off in the US: #82 in 2015, #222 in 2025
• Emily#34“rival, emulator”^*
• Sarah#90“masters, princes”^*
• Samantha#151“listener”^*
• Alexandra#237“to defend + man”^*

Picked from the US top 1,000 in 2025: names Wiktionary also files under where there are enough, topped up with common names whose US popularity since 1990 rose and fell most like Guillermo’s. Place names are only included if they are in the top 300. Rank is US 2025.