Cognomen Thorbjorg (Thorbjorg 
) , in all the world, is an extremely rare family name. Much more frequently, Thorbjorg is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Thorbjorg | United States, Iceland, Norway |
Agustsdottir, Arnadottir, Juliusdottir, Magnusdottir, Gardarsdottir, Einarsdottir, Sigurdardottir, Gudmundsdottir, and Kristjansdottir