Katja Maria Riosianu Medbøe (3 December 1945 – c. 13 November 1996) was a Norwegian actress. She graduated from the Norwegian National Academy of Theatre in 1968, and acted both at Den Nationale Scene and at the National Theatre. Medbøe was best known for her role in the Hustruer-trilogy (Wives), along with Frøydis Armand and Anne Marie Ottersen. She also released records with poetry readings set to music.