Surname Ростислав-Ілля (Ростислав-Ілля 
) , across the world, is an extremely rare cognomen. Much more prevalently, Ростислав-Ілля is the forename as well as the last name. Parts of the name also exists independently as a first name Ростислав, and a first name Ілля.
| VARIANT | COUNTRY |
|---|---|
| Ростислав-Ілля | Ukraine |