Surname Изак (Izak 
, Yzak 
, Изак 
) , in the entire world, is quite a rare family name. The last name Изак is characteristic of Somalia, where it is quite a rare surname, Slovakia, and Slovenia. Not in comparison with a country's population, it is commonest in Somalia, Algeria, and Czechia. More frequently, Изак is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Izak | Poland, Algeria, South Africa, Somalia, Indonesia |
| Yzak | Brazil, China, Mexico, United States, Germany |
| Изак | Russia, Kazakhstan, Kyrgyzstan |
| Izák | Czechia, Slovakia |