(1963), Bullitt (1968), True Grit (1969), M*A*S*H (1970), THX 1138 (1971), Joe Kidd (1972), and Tomorrow (1972), the last of which was developed at the Actors Studio and is his personal favorite.

[1] Duvall won the Academy Award for Best Actor for his role as an alcoholic former country music star in the film Tender Mercies (1983).

Other notable roles include The Outfit (1973), The Godfather Part II (1974), The Conversation (1974), Network (1976), True Confessions (1981), The Natural (1984), Days of Thunder (1990), Rambling Rose (1991), Falling Down (1993), The Paper (1994), Sling Blade (1996), Gone in 60 Seconds (2000), Open Range (2003), Crazy Heart (2009), Get Low (2010), Jack Reacher (2012), and Widows (2018).

[22][23] Around this time, he also roomed with Hackman, while working odd jobs such as clerking at Macy's, sorting mail at the post office, and driving a truck.

[15] Duvall began his professional acting career with the Gateway Playhouse, an Equity summer theater based in Bellport, Long Island, New York.

Arguably his stage debut was in its 1952 season when he played the Pilot in Laughter in the Stars, an adaptation of The Little Prince, at what was then the Gateway Theatre.

[24] After a year's absence when he was with the U.S. Army (1953–1954), Duvall returned to Gateway in its 1955 summer season, playing: Eddie Davis in Ronald Alexander's Time Out for Ginger (July 1955), Hal Carter in William Inge's Picnic (July 1955), Charles Wilder in John Willard's The Cat and the Canary (August 1955), Parris in Arthur Miller's The Crucible (August 1955), and John the Witchboy in William Berney and Howard Richardson's Dark of the Moon (September 1955).

For Gateway's 1956 season (his third season with the Gateway Players), he played the role of Max Halliday in Frederick Knott's Dial M for Murder (July 1956), Virgil Blessing in Inge's Bus Stop (August 1956), and Clive Mortimer in John van Druten's I Am a Camera (August 1956).

By this time (also July 1957), his theatrical credits included performances as Jimmy in The Rainmaker and as Harvey Weems in Horton Foote's The Midnight Caller.

[26][27] Already receiving top-billing at the Gateway Playhouse, in the 1959 season, he appeared in lead roles as Stanley Kowalski in Tennessee Williams' A Streetcar Named Desire (July–August 1959), Maxwell Archer in Once More with Feeling, Igor Romanoff in Peter Ustinov's Romanoff and Juliet, and Joe Mancuso in Kyle Crichton's The Happiest Millionaire (all in August 1959).

[28] At the Neighborhood Playhouse, Meisner cast him in Tennessee Williams' Camino Real and the title role of Harvey Weems in Foote's one-act play The Midnight Caller.

[26][27][29][30][31][32][33] Duvall made his off-Broadway debut at the Gate Theater as Frank Gardner in George Bernard Shaw's Mrs. Warren's Profession on June 25, 1958.

His other early off-Broadway credits include the role of Doug in the premiere of Michael Shurtleff's Call Me By My Rightful Name on January 31, 1961, at One Sheridan Square and the role of Bob Smith in the premiere of William Snyder's The Days and Nights of BeeBee Fenstermaker on September 17, 1962, until June 9, 1963, at the Sheridan Square Playhouse.

His most notable off-Broadway performance, for which he won an Obie Award in 1965 and which he considers his "Othello", was as Eddie Carbone (again) in Miller's A View from the Bridge at the Sheridan Square Playhouse from January 28, 1965, to December 11, 1966.

On February 2, 1966, he made his Broadway debut as Harry Roat, Jr in Frederick Knott's Wait Until Dark at the Ethel Barrymore Theatre.

His appearances during this time include performances on Alfred Hitchcock Presents, Naked City, The Untouchables, Route 66, The Twilight Zone, Combat!, The Outer Limits, The Fugitive, T.H.E.

He was the notorious malefactor "Lucky" Ned Pepper in True Grit (1969), in which he engaged in a climactic shootout with John Wayne's Rooster Cogburn on horseback.

In 1976, Duvall played supporting roles in The Eagle Has Landed, and as Dr. Watson in The Seven-Per-Cent Solution with Nicol Williamson, Alan Arkin, Vanessa Redgrave and Laurence Olivier.

(Pause) Some day this war is going to end...Duvall received a BAFTA Award nomination for his portrayal of detestable television executive Frank Hackett in the critically acclaimed film Network (1976) and garnered an Oscar nomination for Best Actor in a Leading Role in The Great Santini (1979) as the hard-boiled Marine Lt. Col. "Bull" Meechum.

He also co-starred with Laurence Olivier and Tommy Lee Jones in The Betsy (1978) and portrayed United States President Dwight D. Eisenhower in the television miniseries Ike (1979).

Duvall continued appearing in films during the 1980s, including the roles of a detective in True Confessions (1981), a disillusioned sportswriter Max Mercy in The Natural (1984) and Los Angeles police officer Bob Hodges in Colors (1988).

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.

[37] In 1989, Duvall appeared in the miniseries Lonesome Dove in the role of Captain Augustus "Gus" McCrae, Texas Rangers (retired).

He received Oscar nominations for his portrayals of evangelical preacher Euliss "Sonny" Dewey in The Apostle (1997)—a film he also wrote and directed—and lawyer Jerome Facher in A Civil Action (1998).

He continued his film roles by appearing as a mechanic in Gone in 60 Seconds (2000), a soccer coach in A Shot at Glory (2000), a scientist in The 6th Day (2000), a police officer in John Q.

"[48] Duvall met his first wife, Barbara Benjamin,[3] a former announcer and dancer on The Jackie Gleason Show, during the shooting of To Kill a Mockingbird.

[3] In 2005, Duvall married his fourth wife, Luciana Pedraza, granddaughter of Argentine aviation pioneer Susana Ferrari Billinghurst.

[58] In September 2008, he appeared onstage at a John McCain–Sarah Palin rally in New Mexico, and he endorsed Republican presidential nominee Mitt Romney in 2012.

[62][63] In May 2009, Duvall spoke for historic preservation against Walmart's proposal to build a store across the road from the entrance to the Wilderness Battlefield national park in Orange County, Virginia.

[66] Duvall has received numerous accolades for his acting including an Academy Award for Best Actor for his role as an alcoholic former country music star in the drama Tender Mercies (1983).