boy name · Latin origin
Rex
/ REKS /
Meaning
Rex means King (Latin).
Gender
Boy
Origin
Latin
Pronunciation
REKS
Popularity
#859 · U.S. boys (2025)
Popularity of Rex in the US, 1880–2025
Rex first appears in US records in 1880. It peaked in 1951, when 1,503 boys were given the name; in 2025 there were 281.
Source: US Social Security Administration.
What does Rex mean?
Rex is the Latin word for “king.”
Frequently asked questions
What does the name Rex mean?
Rex means King. Rex is the Latin word for “king.”
What is the origin of the name Rex?
Rex is of Latin origin.
How do you pronounce Rex?
Rex is pronounced “REKS.”
Is Rex a boy or a girl name?
Rex is most commonly used as a boy name.
How popular is the name Rex?
In 2025, Rex ranked #859 among boys’ names in the United States, according to U.S. Social Security Administration data.
When was the name Rex most popular?
Rex was most popular in 1951, when about 1,503 US babies were given the name that year, according to US Social Security Administration records.