Caius
Boy name · Latin · pronounced KY-uss
Verified name
What does Caius mean?
Rejoice, happy
Origin and language
Popularity in the United States
Ranked No. 689 in the U.S. in 2025, so it is moderately common. Source: U.S. Social Security Administration data.
Popularity in England and Wales
No. 976 in England and Wales in 2025
Contains Office for National Statistics data licensed under the Open Government Licence v3.0.
Related names, nicknames, and variants
Nickname: Cai
Variant: Gaius
Related: Kai
Using Caius across cultures
Ancient Roman praenomen with literary and historical pedigree.
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