Rosenberger is a Germanic-language family name derived from a toponym Rosenberg + the ending er, with the principal meaning "one from Rose Mountain". However, as a toponym Rosenberg (Rose Mountain), may have originally meant "death mountain" or simply "red hill", from rot + berg.
Today there are many people around the world whose central European ancestors adopted the surname, including many Germans. It is, additionally, used by many Ashkenazi Jews.