After graduating from high school, Marc Gruppe studied theatre and modern German literature. In the course of numerous internships, he gained detailed knowledge of multiple areas of a functioning theatre business.

Marc Gruppe has been a playwright since his teenage years. His first play, "The Devil with the Three Golden Hairs," premiered successfully on November 16, 1991 at the Forum Leverkusen. Since 1997 he has been publishing theater versions of famous children's classics (e.g. by the Brothers Grimm, Charles Dickens, Gerdt von Bassewitz, E. T. A. Hoffmann, Frances Hodgson Burnett and Ralf Isau) at the Vertriebsstelle und Verlag Deutscher Bühnenschriftsteller und Bühnenkomponisten (VVB) in Norderstedt.

He is one of the most frequently performed German authors in the genre of Christmas fairy tales and children's theatre (including the premiere of "Der Drache Gertrud" at the Staatstheater Braunschweig in 2001, and "Peterchens und Annelieses Mondfahrt" at the Landesbühnen Sachsen-Anhalt and the Waldau Theater in Bremen).

In January 2003, Marc published his first play for adults, "Edgar Wallace - Das indische Tuch".
In the same year he also founded the label Titania Medien together with Stephan Bosenius, which specialises in immersive audio dramatisations. Since then he has been the label's sole writer, director and producer. As of 2025, the label has released well over 300 audio dramatisations in the series Gruselkabinett, Sherlock Holmes, Grimms Märchen, Titania Special and Anne auf Green Gables. Since 2025, he has also been working as an author and editor of Titania Medien's Sherlock Holmes novels.

In September 2011 Marc Gruppe's stage adaptation of the bestselling thriller "Der Seelenbrecher" by Sebastian Fitzek premiered in Braunschweig.

From 2002 to 2016 Marc Gruppe was the artistic director of the Volksbühne Bergisch Neukirchen in Leverkusen. During this time, he staged, inter alia, "Das indische Tuch", "Das Haus in Montevideo", the Kálmán operetta "Die Herzogin von Chicago", the musicals "Der König und ich - Anna und the König von Siam", "Anatevka", "Kiss Me Kate!", "My Fair Lady", "The Sound of Music - Die Trapp-Familie", "Camelot", "Das Feuerwerk", "Das Wirtshaus im Spessart", "Sissy", "Blondinen bevorzugt", "Die Geisha" and "Cinderella".

In September 2016, Marc Gruppe's stage version of Sebastian Fitzek's debut novel "Die Therapie" premiered successfully at the Berliner Kriminal-Theater. Further productions of the stage thriller followed,...