Den hemmelighetsfulle leiligheten () is a 1948 Norwegian drama film directed by Tancred Ibsen, starring Ola Isene and Sonja Wigert. The film is based on a short story by Kristian Elster. A bachelor in his forties buys an apartment owned by an artist who died a sudden death. The peculiar atmosphere of the place, and the sudden appearance of the artist's girlfriend, shakes the conservative man out of his habits.