Family name Koset (โกเศศ 
, Koset 
) , throughout the world, is a rare surname. The cognomen Koset is characteristic of Thailand, where it is a rare surname, Malaysia, where it is a very rare surname, and Peru, where it is an extremely rare surname. Not in comparison with a country's population, it most frequently occurs in Thailand, China, and Malaysia. Also, Koset is the forename as well as the last name.