Rosalie Thomass, born August 14, 1987, already entered the stage during her school days. She was not only the member of a rock band but also started to perform at Munich"s Volkstheater in 1995. In 2001, Thomass became a cast member of the youth theatre group at Munich"s Kammerspiele. At the same time, she also took professional acting lessons.

After playing minor roles in several TV movies, Thomass soon made her breakthrough performance in the leading female role of the TV crime movie "Polizeiruf 110 – Er sollte tot". Directed by Dominik Graf, Thomass portrayed a psychologically unstable prostitute who gets involved in a murder case. This role won her German cinema"s promotional award, a Grimme award, the Bavarian TV award, and a German film award.

In 2007, Thomass made her movie debut in Marcus H. Rosenmüller"s "coming of age" film "Beste Zeit". She also had a leading role in the films" sequel "Beste Gegend". Her third role (albeit a very small one) under the direction of Marcus H. Rosenmüller was in "Räuber Kneißl". In October 2008 Rosalie Thomass can be seen in Max Färberböck"s drama "Anonyma – Eine Frau in Berlin", based on the bestselling book of the same title.