Cognomen Круглиаков (Kruglyakov 
, Круглиаков , Krugliakov 
) , all around the world, is a rare last name. The cognomen Круглиаков is characteristic of Lithuania, where it is a rare surname, Estonia, and Israel. Not in comparison with a country's population, the name is most common in Russia, Israel, and Lithuania.
| VARIANT | COUNTRY |
|---|---|
| Kruglyakov | Spain, Israel, Belarus, United States, Russia |
| Круглиаков | Russia |
| Krugliakov | United States, Lithuania, China |
Kruhliakov, and Kruhlyakov