Selma Rainio (until 1905 Lilius, 21 March 1873, Saarijärvi, Finland – 5 January 1939, , South West Africa) was a Finnish missionary with the Finnish Missionary Society, the first Finnish medical missionary, who founded the Onandjokwe Hospital in the Ondonga tribal area in Ovamboland. She also worked in the Engela Hospital. In Ovamboland, she was known as Kuku Selma ‘grandmother Selma’.