Family name Piyak (Piyak 
, Пияк 
) , in all the world, is a rare cognomen. The last name Piyak is characteristic of Ukraine, where it is a rare surname, Russia, where it is a very rare surname, and Philippines. Likewise, Piyak is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Piyak | India, Nigeria, Russia, Philippines |
| Пияк | Russia, Ukraine |