Rex

What Rex means

Means “king”

From Latin rēx (“king”).

Source: Wiktionary, “Rex” (revision 93487566), CC BY-SA 4.0. Quoted from the etymology; we don’t write our own.

How popular is Rex?

US: Falling: down from #679 in 2015. England & Wales: Steady: #212 in 2015, #228 now.

Biggest US share so far: 1951, when 1,503 boys got the name (#170 that year). First in the US records in 1880.

How common

• About 1 in 6,079 baby boys in the US in 2025
• About 1 in 1,253 baby boys in England and Wales in 2025
• About 1 in 4,910 baby boys in Scotland 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 UT (0.66 per 1,000 boys), OK (0.45 per 1,000 boys), AZ (0.37 per 1,000 boys) in 2025.

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

US vs UK

Rex is #859 in the US and #228 in England & Wales (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 Rex were boys.

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

How to say it

IPA from Wiktionary.

Other spellings parents chose in 2025

• Roux14 US · 32 E&W
• Rox0 US · 7 E&W
• Rexx5 US

Names that sound the same and differ by a letter or two, with baby counts for the same sex. US and E&W counts.

If you like Rex

Boys

• Cassius#582Editor’s note Up from #644 in 2015 to #582 in 2025 in the US
• Leo#19“lion”^*
• Lucas#10Editor’s note Up from #16 in 2015 to #10 in 2025 in the US. About 1 in 170 US boys in the 2025 records
• Roman#42Editor’s note Climbing fast in the US: #102 in 2015, #42 in 2025
• Lucian#462Editor’s note Up from #633 in 2015 to #462 in 2025 in the US
• Lionel#659“lion”^*

For a sister

• Beatrice#508“she who makes happy”^*
• Renata#481“reborn”^*
• Leona#429Feminine form of Leo, meaning “lion”^*
• Camilla#361Editor’s note Up from #374 in 2015 to #361 in 2025 in the US
• Liana#385Editor’s note Up from #525 in 2015 to #385 in 2025 in the US
• Aurelia#290“golden”^*

Picked from the US top 1,000 in 2025: names Wiktionary also files under Latin, whose US popularity since 1990 rose and fell most like Rex’s. Rank is US 2025.