Cognomen Krugliak (Krugliak 
, Кругляк 
) , around the world, is quite a common last name. The last name Krugliak is characteristic of Ukraine, where it is quite a rare surname, Russia, and Kazakhstan, where it is a rare surname.
| VARIANT | COUNTRY |
|---|---|
| Krugliak | China, Argentina, Romania, United States, Albania |
| Кругляк | Kazakhstan, Belarus, Kyrgyzstan, Russia, Ukraine |