Family name Koir (Koir 
) , in all the world, is a rare cognomen. The surname Koir is habitual in Slovenia, where it is a rare surname, Indonesia, where it is a very rare surname, and Malaysia. Not in comparison with a country's population, it is commonest in Indonesia, India, and Slovenia. Much less frequently, Koir is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Koir | Indonesia, Slovenia, India, Malaysia, United States |