Osa Massen (1914-2006), born Aase Madsen Iversen, was a Danish-born actress who started out as a newspaper photographer. Her film debut was in a Danish produced movie entitled Kidnapped, a comedy with no connection to the Robert Louis Stevenson novel of the same name. She was spotted by Hollywood talent scouts on the lookout for potential European starlets in the vein of Greta Garbo and Ingrid Bergman and received a contract from 20th Century-Fox. She was often cast in unsympathetic roles, such as femme fatales and homewreckers. In the 1950s, she mostly worked in television, where her credits included Richard Diamond, Private Detective, Wagon Train, and Perry Mason.
Due to the similarity of their names, she was sometimes confused with fellow actress Ona Munson.