Cognomen Кои (Koi 
, Кои 
) , in the world, is a common surname. The last name Кои is habitual in Fiji, where it is quite a common surname, Papua New Guinea, and Malaysia, where it is quite a rare surname. Measured by absolute frequency, it is the most numerous in Malaysia, Indonesia, and Kenya. Likewise, Кои is the forename as well as the last name.