Family name Donjak (Donjak 
) , in the entire world, is a rare last name. The cognomen Donjak is habitual in Bosnia and Herzegovina, where it is quite a rare surname, Germany, where it is a very rare surname, and Thailand. Likewise, Donjak is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Donjak | Bosnia and Herzegovina, Thailand, India, Germany |