Surname Ivanjak (Ivanjak 
, Иваняк 
) , across the world, is a very rare last name. The surname Ivanjak is habitual in Croatia, where it is a rare surname, Russia, where it is a very rare surname, and Germany, where it is an extremely rare surname.
| VARIANT | COUNTRY |
|---|---|
| Ivanjak | Germany, Croatia |
| Иваняк | Russia, Ukraine |