Cognomen Sladoja (Sladoja 
) , in all the world, is a very rare last name. The cognomen Sladoja is characteristic of Croatia, where it is quite a rare surname, and Canada, where it is an extremely rare surname. Much less frequently, Sladoja is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Sladoja | Croatia, United States, Canada |