Ritva Koivula was born in the Finnish Russian city of Vyborg and took up swimming after World War II, winning the Finnish national junior titles in 100 metre freestyle and backstroke events in 1948 and 1949. Although she never won a senior national title, she represented Finland internationally at the 1949 and 1951 Nordic championships, as well as the 1952 Helsinki Olympics. At the latter, she was 40th individually in the 100 metres freestyle and 13th and last, alongside Raili Riuttala, Anneli Haaranen, and Ritva Järvinen, in the 4x100 metres freestyle relay. She retired from active competition soon after the Games.