I always considered myself as a character actor. I always try to be versatile to show different sides of human experience.

Duvall founded a production company Butcher's Run Films. D. Director Bruce Beresford too said the transformation was so believable to him that he could feel his skin crawling up the back of his neck the first day of filming with Duvall.

A veteran actor Duvall has starred in some of the most acclaimed and popular films and TV shows of all time among them The Twilight Zone The Outer Limits To Kill a Mockingbird THX 1138 Joe Kidd The Godfather The Godfather Part II MASH Network The Apostle True Grit The Conversation Apocalypse Now Falling Down Tender Mercies The Natural and Lonesome Dove. Since then Duvall has continued to act in both film and television with such productions as Tender Mercies (1983) (for which he won an Academy Award) The Natural (1984) Colors (1988) the television mini-series Lonesome Dove (1989) Stalin (1992) The Man Who Captured Eichmann (1996) A Family Thing (1996) The Apostle (1997) (which he also wrote and directed) A Civil Action (1998) Gods and Generals (2003) Broken Trail (2006) and Get Low (2010). He began appearing in theater during the late 1950s moving into television and film roles during the early 1960s in such works as To Kill a Mockingbird (1962) (as Boo Radley) and Captain Newman M.