Cognomen Ильиш (Ilich 
, Ilish 
, Ильиш 
) , worldwide, is quite a rare family name. The last name Ильиш is habitual in Serbia, where it is quite a rare surname, Slovenia, and Bulgaria. Not in comparison with a country's population, the name is most common in the United States, Mexico, and Australia. Likewise, Ильиш is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Ilich | Australia, Mexico, Serbia, United States, Peru |
| Ilish | Democratic Republic of the Congo, Mexico, United States, Peru, Venezuela |
| Ильиш | Russia |