Marianne Schell is educated at Musikhögskolan, solistlinjen, and Teater- och Operahögskolan in Gothenburg. She made her debut in 1975 at Stora Teatern as Elsalill in Herr Arnes penningar. Next followed a large number of roles such as Amanda in Tintomara, the female title role in Brudköpet and Flickan i ögat, Papagena in Die Zauberflöte, Micaela and Mercedes in Carmen, Tigrinnan in Animalen, Pallas Athena in The Return of Odysseus, Prins Orlofsky in Die Fledermaus in Stora Teatern's production at Scandinavium, Sophie in Werther, Composer in Ariadne auf Naxos, Cherubin in Le Nozze di Figaro, Juno in Orpheus in the Underworld and Frau Peachum in Der Dreigroschenoper.
At the Göteborg Opera Marianne Schell has sung Cherubin and Marcellina in Le Nozze di Figaro, Mary in Der Fliegender Holländer, Suzuki in Madama Butterfly, Eberharda Lindberg in Äppelkriget, Herodias in Salome, The Mother in Les Contes d'Hoffmann, Mrs Sedley in Peter Grimes, Flora in La traviata, Margret in Wozzeck, Third Lady in Die Zauberflöte, Klytaimestra in Elektra, Mme Thérnardier in Les Misérables, Mother de Croissy in Les Dialogues des Carmelites, A Mother in Lulu, Annina in Der Rosenkavalier, Leona in La Belle Helene and The Old Countess in Pique Dame.
She has also sung in a number of concerts. Marianne Schell has been a guest soloist at Drottningholmsteatern and Riksteatern, and been a solist at romance and orchestra concerts both in Sweden and abroad.