Family name Roulf (Roulf 
) , across the world, is an extremely rare cognomen. The cognomen Roulf is habitual in Venezuela, where it is an extremely rare surname, Brazil, and the United States. Predominantly, Roulf is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Roulf | Brazil, United States, Democratic Republic of the Congo, Peru, South Africa |