Carl Wilhelm Ossian Mesterton (born 21 November 1929 in Helsinki) is a Finnish television director, screenwriter and actor. The most well-known and popular of Mesterton's TV directions are "Metsolat" (1993–1995), a family chronicle of a small-scale farming family in Kainuu, and "Hovimäki" (1999–2003), a drama following the stages of the Lindhof noble family and the Seppä croft family in three different centuries. Mesterton has written the series together with his wife Anna-Lisa Mesterton, among others.

Mesterton has also starred in bigger and smaller roles in films and television, such as Markku Pölönen's "Onnen maassa" (1993), Jaakko Pakkasvirta's Kafka filmatization "Linna" (1986) and in the TV series "Barr" (1984) directed by Reima Kekäläinen and dramatized from Paavo Haavikko's own novel. .

Mesterton also worked as one of the assistant directors in the film "Reds" (1981), partly shot by Warren Beatty in Finland.