Rex
Feminine · Latin roots · “King (Latin)”
Rex is given to boys far more often — 60,449 boys against 141 girls since 1880. See Rex as a boy name
Rex entered the US charts in 1921, peaked at #3362 in 1925, is rarely given in 2025 — given to only a few children a year.
How old is the name Rex?
Rex first appears in US birth records in 1921 — 104 years ago. The typical Rex alive today was born around 1954, making them about 71 years old. Fewer than a hundred people named Rex are estimated to be alive in the US today — a true one-of-a-kind name.
When was the name Rex most popular?
Rex peaked in 1925, reaching #3362 nationally. See the whole 1925 chart.
Lists built from the same records:
Where it comes from
From regere (Latin, to rule) to Rex
The story of Rex
Rex is the Latin noun for king, from the verb regere, to rule, and it belongs to a very old word family: Sanskrit rājan and Irish rí are its cousins. Rome used it for its earliest kings, then kept it in legal and priestly formulas — the rex sacrorum held a religious office long after the monarchy was gone — and it stayed alive in Latin mottoes and inscriptions through the Middle Ages. It began appearing as an English given name in the nineteenth century, alongside the same taste for plain Latin words that gave us Regina, and it doubled as a short form of Reginald and Rexford. American records show it in continuous use from the earliest years they cover, with its strongest showing around the middle of the twentieth century.
Meaning
King (Latin)
Latin rex, genitive regis, from regere, to rule.
How the name formed
- regereLatin, to rule
- rexLatin, king
- Rex
Related forms: Rex · Rex · Rex · Rey
Pronouncing Rex
REKS
One syllable, said exactly as written. No competing pronunciations in English, and it survives most other languages unchanged.
Nicknames for Rex
Moderate
What the data says
146 years of official birth records
The long climb, and where it stands now
The same years in position rather than babies
- First recorded
- 1921
- Most girls named
- 196110 — the highest on record
- Peak rank
- #3362reached in 1925
- Change vs 1980
- +20.0%6 in 1984, from 5
Rank is a position, a count is a headcount, and they move independently — a name can hold its rank while the number of babies behind it falls. Source: U.S. Social Security Administration.
Rex in other languages
The same name elsewhere
- Rex in Latin — same name
- Rex in German — same name
- Rex in Dutch — same name
- Rey in Spanish — related form
Rexs among us
Fewer than a hundred people named Rex are estimated to be alive in the US today — a true one-of-a-kind name.
Estimated from SSA birth records and published actuarial life tables. Method
Is it right for you
Questions parents actually ask
Fashion outlook
Rex sits outside the current charts, and that is its own kind of answer: naming cycles can only date the names they carried up. A name this rare has no decade stamped on it — it cannot go out of fashion, because it was never in.
Based on 146 years of naming cycles. How we read them
Nobody names a baby alone.
Put Rex to the vote.
Add it to a family vote or a couple’s swipe deck — the other person gets one card, a simple answer and room to say why. No app, no account for them.
Only the people you invite can see your list.
Already decided on Rex? Hide it among decoys and let them guess.
What they receive
Someone added a name to your list
Rex
Feminine · Latin roots
Frequently asked
- How many Rexs are there in the world?
- No country counts the world's names, so there is no worldwide figure — anyone quoting one is estimating. Fewer than a hundred people named Rex are estimated to be alive in the US today — a true one-of-a-kind name.
- How popular is the name Rex in 2025?
- Rex is rarely given in the US today — it does not rank in the top 2000 girl names.
- Will my child share the name Rex with classmates?
- Rex will almost certainly be the only one in school.
More R names
The most-given names starting with R, all years combined.
Ruth#173 · Rebecca#349 · Rachel#250 · Rose#114 · Ruby#64 · Robin#704 · Rita#1285 · Rhonda#6116
Looking for what else is popular rather than what resembles Rex? See the current top 100.
Choosing between Rex and another name?
See them side by side — full stats, history and a gentle verdict.
Compare side by sideIn a hurry? Just pick a winner — one tap, no sign-up, and you see how everyone else voted.
Weighing a whole shortlist? Add the rest in the builder, or settle it with a bracket.
Cast your vote
Which one would you pick?
Your gut first, the numbers after — the split shows once you pick.
US figures from the Social Security Administration. 1880–2025. Data & methodology
No advertising trackers and no data sellinghow we handle your dataindependent and founder-run, about Name Battle