What does Caio mean?
Caio /caio/ [3 sylls.] as a boys' name. Caio's name origins are Welsh and Latin, and the meaning of Caio is "happy". Caio is an alternate spelling of Caeo (Welsh) with the suffix -io. Caio is also a variation of Cai (Welsh). Caio is also used as a derivative of Caius (Latin) and Gaius (Latin).
How popular is Caio?
Caio is an uncommonly occurring first name for men. Caio is an unusual last name too for both adults and children. (2000 U.S. Census)
Below is a graphed comparison of the usage of Caio and associated names. Popular variation forms of Caio (not in Top 1000) are Kai (#177 in 2014) and Kay. Forms like Keyes are uncommon. These boy names were at the apex of their popularity in 2014 (usage of 0.4115%), except for the form Kay which has become less stylish. Kai (#177) is the most contemporarily stylish name for newborns among these. (Top 1000 Birth Names Records, 2014)