Surname Davidiak (Davidiak 
, Давидяк 
) , all around the world, is a rare cognomen. The surname Davidiak is habitual in Ukraine, where it is quite a rare surname, Russia, where it is a very rare surname, and Georgia. In absolute terms, it is the most numerous in Ukraine, Russia, and Kazakhstan.
| VARIANT | COUNTRY |
|---|---|
| Davidiak | Georgia, United States |
| Давидяк | Russia, Ukraine, Kazakhstan |