Family name Kosoian (Косоян 
, Kosoian 
) , in the world, is a rare surname. The family name Kosoian is habitual in Russia, where it is a very rare surname, Georgia, and Ukraine. Not in comparison with a country's population, it is commonest in Russia, Ukraine, and the United States. Also, Kosoian is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Косоян | Russia, Armenia, Ukraine |
| Kosoian | United States, Georgia |