Last name ก้อย (Koi 
, Koiu 
, Koiy 
) , in the world, is a common cognomen. The surname ก้อย 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, this name is the most popular in Malaysia, Indonesia, and Kenya. Also, ก้อย is the forename as well as the last name.