Surname Koiyan (Koiyan 
) , around the globe, is a very rare cognomen. The surname Koiyan is habitual in Northern America, particularly the United States, where it is an extremely rare surname. More prevalently, Koiyan is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Koiyan | India, Liberia, United States |