Family name 凱思 (Keith 
, Cath 
, 凱思) , in the entire world, is a common cognomen. The cognomen 凱思 is habitual in British Virgin Islands, where it is quite a common surname, Jersey, and Macao (explore the name in all countries). Not in comparison with a country's population, this name is the most popular in the United States, the United Kingdom, and Canada. More prevalently, 凱思 is the forename as well as the last name.