Cognomen Косиор (Kosior 
, Косиор 
) , all over the world, is quite a rare surname. The cognomen Косиор is habitual in Poland, where it is quite a rare surname, Israel, where it is a rare surname, and Canada. Not in comparison with a country's population, this name is the most popular in Poland, the United States, and Canada. Also, Косиор is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Kosior | Germany, Poland, Canada, United States, France |
| Косиор | Ukraine, Russia |
| елизавета сергеевна косиор Soviet politician (1895-1938), RU (b. 1895) |
|