Rex

boyLatin

Rex is a boy name of Latin origin, meaning “King”.

MeaningKing
GenderBoy
OriginLatin
PronunciationREKS
TraditionModern & Classic
Used inUnited Kingdom, United States, Australia

Meaning and origin of Rex

Rex is simply the Latin word for 'king', and it came into use as an English first name in the nineteenth century. It can also serve as a short form of Reginald. The name has a bold, one-syllable sound and was carried by actors such as Rex Harrison. Many people also know it from the dinosaur Tyrannosaurus rex, 'tyrant lizard king', and from its long use as a dog's name.

Is Rex a religious name?

Rex has no religious background, although in Christian Latin Christ is called Rex, as in the title Christus Rex, 'Christ the King'.

How popular is Rex?

Uncommon but recognisable, with some recent revival in Britain and Australia.

Gifts with the name Rex

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Spellings and variants of Rex

Names similar to Rex

More boy names

Frequently asked questions

What does the name Rex mean?

Rex means 'King'. It is of Latin origin.

Does Rex have a religious meaning?

Rex has no religious background, although in Christian Latin Christ is called Rex, as in the title Christus Rex, 'Christ the King'.

How do you pronounce Rex?

Rex is pronounced REKS.

Is Rex a boy or girl name?

Rex is usually a boy name.

Updated October 2026. Spotted a mistake? Tell us.