Marthe Keller (born 28 January 1945; Basel, Switzerland) is a Swiss actress and opera director. She studied ballet as a child, but stopped after a skiing accident at age 16. She changed to acting, and worked in Berlin at the Schiller Theatre and the Berliner Ensemble. In 2001, Keller appeared in a Broadway adaptation of Abby Mann's play Judgment at Nuremberg as Mrs. Bertholt (the role played by Marlene Dietrich in the 1961 Stanley Kramer film version). She was nominated for a Tony Award as Best Featured Actress for this performance.