boy's name
Rex
REKS
- Origin Latin
- Gender Boy
- Syllables 1
- Letters 3
- Popularity Top 1000 (US)
- Births on record 65,596
the United States
#859
2025 births
Rex means king, and it is the plain Latin nominative — which makes it the pair to Regis, the genitive meaning of the king. Both are on this site, one word in two grammatical cases.
- Rex is a name of Latin origin.
- Peaked in 1952, when 1,505 babies were given the name.
- Its usage has held steady over the past decade.
- Today about 1 in 11,798 babies in the United States is given this name.
- 1 syllable, with the stress on syllable 1.
Rex over time
Births per decade in the United States, 1880s to 2020s. The striped bar is the 2020s, still in progress — it covers 2020 to 2025, not a full ten years.
Show the numbers
| Decade | Births |
|---|---|
| 1880s | 183 |
| 1890s | 305 |
| 1900s | 497 |
| 1910s | 3,253 |
| 1920s | 5,660 |
| 1930s | 5,961 |
| 1940s | 6,682 |
| 1950s | 13,543 |
| 1960s | 8,758 |
| 1970s | 3,366 |
| 1980s | 2,543 |
| 1990s | 1,740 |
| 2000s | 2,048 |
| 2010s | 3,945 |
| 2020s (to 2025) | 2,106 |
What Rex means
Rex means king. The Latin is the ordinary noun in its base form, so the name states the rank directly rather than describing a quality of the person.
Where Rex comes from
Rex is the Latin for a king, from an Indo-European root that also gives the Sanskrit raja, the Gaulish -rix in Vercingetorix, and the Irish rí. Rome expelled its kings in 509 BC and the word became politically radioactive — Caesar's refusal of a crown turned on it, and the title rex sacrorum survived only as a priesthood stripped of power. English use as a given name is nineteenth-century, helped by the legal formula Rex versus the defendant under a king.
Rex in use
Rex peaked in the United States in 1952, when 1,505 babies were registered, and our data marks it stable rather than falling. It now ranks 228th in England and Wales on 217 births — its strongest market by a wide margin — then 390th in Scotland on 9 and 859th in the United States on 281, across 65,596 lifetime births in four of the seven markets we track. Regis, the genitive of the same word, is written up separately.
How popular is Rex?
In 2025, Rex was given to 281 babies in the United States, ranking #859 that year. It is a well-established, commonly used name.
Where Rex is used
US figures omit any name given to fewer than five babies in a year, so the rarest names are absent from the source rather than absent from use. Data & sources.
Names that peaked alongside Rex
These names rose and fell in the same era, which is why they tend to sound like they belong together.
Parents who like Rex also like
Names whose popularity has risen and fallen in step with Rex over the last century — the same taste, a different name.
Rex in other languages
The same name as it is spelled elsewhere — not shortenings, and not different names that merely sound alike. Each one has its own record here.
Sibling names for Rex
Names from the same era that won't rhyme or share an initial with Rex — the two things that make a sibling set grate.
Common questions about Rex
What does the name Rex mean?
King — the plain Latin noun.
Is Rex related to Regis?
The same word in two cases. Rex is the nominative, king; Regis the genitive, of the king.
Why do British court cases say Rex?
Prosecutions are brought in the monarch's name — Rex under a king, Regina under a queen.
Where is Rex most used?
England and Wales at 228th, well above the United States at 859th.
How popular is the name Rex?
In 2025, Rex was given to 281 babies in the United States, ranking #859 that year. It is a well-established, commonly used name.
Is Rex a girl's or a boy's name?
Rex is given almost entirely to boys in birth records.
How many syllables are in Rex?
Rex has 1 syllable.
When was Rex most popular?
Rex peaked in 1952, when 1,505 babies were given the name. Its usage has held steady over the past decade.
Is Rex a good name?
That is not something records can settle, but they can tell you what you would be choosing. Rex currently ranks #228 in the United States. Its usage has held steady over the past decade. Everything else — how it sounds with your surname, who it reminds you of — is yours.