Grusomhetens Teater (Norwegian: Theatre of Cruelty) is a Norwegian theatre company based in Oslo's Hausmania cultural centre. The company produced its first performance in collaboration with Trøndelag Teater in 1989, and was established as an independent group in 1992. The theater's manager and director is Lars Øyno. In 2002 the theater company received support from the Norwegian Arts Council to launch its own performing space in Hausmania.
Grusomhetens Teater is inspired by Antonin Artaud's ideas of a double and physical theater, where the body's musical breathing and expressions are actions meant to generate deconstruction and reteatralization.
Since its foundation and until today the theater produced 22 performances. One of the theater's greatest successes has been Henrik Ibsen's unfinished opera libretto The Mountain Bird. In 2009 the theater made history premiering this unused and forgotten Ibsen play, exactly 150 years after the unfinished manuscript was written and set aside.
The company's productions include: