Kinnunen won the Nordic Challenge Cup in 1969, the Interserie from 1971–1973, and helped Porsche to take the World Sportscar Championship for manufacturers in 1970 (drivers championships were not awarded until 1981). In 1974, he switched to Formula One. He was the last driver to compete in Formula One using an open-face helmet.
- "Leo Kinnunen – Biography". F1 Rejects. Archived from the original on 2006-11-06. Retrieved 2007-01-28.
- "Ensimmäinen suomalainen F1-kuljettaja Leo Kinnunen on kuollut". Ilta-Sanomat (in Finnish). 26 July 2017. Retrieved 26 July 2017.