Family name Karolj (Karolj 
) , in all the world, is a rare cognomen. The family name Karolj is habitual in Southern Europe, particularly Serbia, where it is quite a rare surname, and Croatia, where it is a rare surname. Likewise, Karolj is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Karolj | Croatia, Sweden, Serbia, Germany, Canada |