Aarne Haapakoski (1904 in Pieksämäki, Southern Savonia – 1961 in Málaga) was a Finnish pulp writer. He is perhaps best known for a detective fiction series about architect/detective "Klaus Karma" and a science fiction series about a robot named "Atorox." The Atorox stories were written under the pseudonym Outsider. The Atorox Award for Finnish science fiction is named for Atorox.