Rex
Rex was the 859th most popular name for boys in 2025, given to 281 babies. Its best year was 1951, when it ranked 170th with 1,503 babies. Over the last ten years it has moved down 179 places. More babies were named Rex in the 1950s than in any other decade.
Meaning king (Latin) · Latin
Say it REKS /rɛks/
- Rank in 2025
- #859 boys, down 176 places since 2020
- Babies in 2025
- 281boys
- Girls and boys
- Almost always a boy’s name2021–2025
- Peak year
- 19511,503 babies
- Total since 1880
- 60,590babies recorded
What does the name Rex mean?
Rex is the Latin word for king, which Wiktionary says was coined as an English given name in the 19th century. Latin rex is related to Sanskrit raja and to Old French roi, the source of Roy. Wiktionary notes that the name is rarely given today, though US records show it continuously since 1880 and more often in recent years. It was most common in the early 1950s.
rēx (Latin, “king”)
How sure is this? Well established.
Related names: Roy, Regis, Rey, Regina.
See also: Latin names, names that mean king or queen.
Sources for this meaning
- Wiktionary, entry 'Rex' (English section), Wiktionary (CC BY-SA 4.0; facts restated, no text reused)
- Dictionary of Medieval Names from European Sources, ed. S. L. Uckelman, Edition 2023 no. 1, s.v. 'Regina', DMNES (Durham University)
- US Social Security Administration, national baby-name data 1880-2025 (yob*.txt), team3 computation of first year recorded, US Social Security Administration (public domain)
Rex popularity since 1880
A few girls are given the name too: 141 since 1921.
| Year | Rank (boys) | Babies (boys) |
|---|---|---|
| 2025 | #859 | 281 |
| 2020 | #683 | 377 |
| 2010 | #704 | 332 |
| 2000 | #1,213 | 112 |
| 1990 | #664 | 232 |
| 1980 | #488 | 300 |
| 1970 | #362 | 507 |
| 1960 | #214 | 1,314 |
| 1950 | #196 | 1,069 |
| 1940 | #228 | 547 |
| 1930 | #235 | 540 |
| 1920 | #210 | 614 |
| 1910 | #309 | 65 |
| 1900 | #268 | 59 |
| 1890 | #320 | 30 |
| 1880 | #519 | 13 |
How popular is Rex, counting every spelling?
Rex is the most common spelling of a name family that ranked #820 for boys in 2025 once every spelling is counted together, compared with #859 for Rex on its own. Together these spellings went to 286 boys in 2025.
| Spelling | Babies 2025 | Official rank | Babies 2021–2025 |
|---|---|---|---|
| Rex | 281 | #859 | 1,729 |
Spellings count together when they sound the same in American English and are used for the same sex; nicknames and forms that sound different (such as Theo and Theodore) are kept apart. How we group spellings.
How many kids will share the name Rex?
281 of the 3,606,400 babies born in the US in 2025 were named Rex (0.08 per 1,000 births). For a boy named Rex born in 2025, the chance that another child with the same name is in a class of 20 children the same age is under 1 in 50. If every grade liked the name as much as the 2025 babies do, only about one elementary school in 30 (of 430 pupils) would have a child named Rex.
Shares of all registered births (NCHS); classes assumed to be children born the same year. How we estimate this.
How old are people named Rex?
About 34,700 people born in the US named Rex are alive today, with a median age of 61; half are between 31 and 71. That makes Rex a name most people associate with older generations. The wide spread shows a name popular in two different eras.
Babies given the name each year (SSA) times the share of that birth year still alive (SSA life tables). Counts people born in the US only. Method.
Rex by state
How common Rex was among boys born in each state in 2021–2025. It is notably more common than nationally in Utah (3.5×), Oregon (2.0×), Louisiana (2.0×), Iowa (1.9×), Arizona (1.8×). It is least common, relative to the national rate, in New Jersey, Kansas, Connecticut.
Names with a similar history
These names rose and fell in step with Rex: their share of US boys followed the most similar curve since 1880. If you like Rex, they share its era and feel.
Middle names for Rex · Sibling names for Rex
Questions about the name Rex
What does Rex mean?
Rex means “king (Latin)” (Latin origin). Certainty: well established.
How popular is the name Rex?
Rex was the 859th most popular name for boys in 2025, given to 281 babies. Its best year was 1951, when it ranked 170th with 1,503 babies. Over the last ten years it has moved down 179 places. More babies were named Rex in the 1950s than in any other decade.
Is Rex a boy or girl name?
In 2021–2025, almost always a boy’s name given the name Rex in the US.
Where is Rex most popular?
In 2021–2025, Rex was most common in Utah (0.69 per 1,000 boys), followed by Nebraska and Oregon.