Cognomen Ryjko (Ryjko, Рыжко 
) , in the world, is quite a rare family name. The cognomen Ryjko is habitual in Belarus, where it is quite a rare surname, Georgia, where it is a rare surname, and Russia. In absolute terms, this name is the most popular in Belarus, Russia, and Kazakhstan.
| VARIANT | COUNTRY |
|---|---|
| Рыжко | Kazakhstan, Russia, Kyrgyzstan, Georgia, Belarus |