He was nominated for a Golden Globe Award for Best Actor – Motion Picture Drama for his starring role in the 1960 film version of D. H. Lawrence's Sons and Lovers.

His television roles include Rear Admiral Albert "Al" Calavicci in Quantum Leap (1989–1993), Navy Secretary Edward Sheffield on JAG (2002–2004), and Brother Cavil on Battlestar Galactica (2004–2009).

[3] Stockwell was born into a family of entertainers in the North Hollywood section of Los Angeles,[4] and grew up between there and New York City.

His father appeared in New York productions of Carousel and Oklahoma!, and was the voice of the Prince in Disney's 1937 animated feature film Snow White and the Seven Dwarfs.

His stepmother, Nina Olivette, was an actress, comedian, singer, and toe dancer in burlesque and theater in New York and throughout North America.

Producer Joe Pasternak gave him a bigger part in Anchors Aweigh (1945) with Frank Sinatra and Gene Kelly, where he played the nephew of Kathryn Grayson.

[14] The film was popular, and MGM gave him a key role in The Green Years (1946) as Robert Shannon, an Irish Catholic orphan who grows up in a Scottish Presbyterian household.

He had supporting roles in The Arnelo Affair (1947), The Romance of Rosy Ridge (1947) (as Janet Leigh's brother), and Song of the Thin Man (1947), billed fourth as the son of William Powell and Myrna Loy's characters.

He was then borrowed by RKO Pictures to play the title role in The Boy with Green Hair (1948) directed by Joseph Losey, a notorious flop for the Dore Schary regime.

"[13] Back at Fox, he was cast as Lionel Barrymore's grandson and Richard Widmark's protégé in Down to the Sea in Ships (1949), before supporting Margaret O'Brien at MGM in The Secret Garden (1949), a box office disappointment.

[18] Stockwell was top billed in The Happy Years, which lost a considerable amount of money for the studio, but then played the title role in Kim (1950) alongside Errol Flynn and Paul Lukas, a big commercial success.

Stockwell graduated from Alexander Hamilton High School in Los Angeles, and attended the University of California, Berkeley for a year before dropping out.

[13] He continued to work mostly on television, including episodes of Checkmate, The DuPont Show with June Allyson, Outlaws, Alfred Hitchcock Presents, Hallmark Hall of Fame (The Joke and the Valley), Bus Stop, The Twilight Zone ("A Quality of Mercy"), Alcoa Premiere, The Alfred Hitchcock Hour, and The Dick Powell Theatre.

He appeared in an adaptation of Eugene O'Neill's play Long Day's Journey Into Night with Katharine Hepburn, Ralph Richardson and Jason Robards, under the direction of Sidney Lumet.

"[18] He subsequently guest starred on Combat!, The Greatest Show on Earth, The Defenders, The Eleventh Hour, Kraft Suspense Theatre, Burke's Law, had a six-episode arc on Dr. Kildare, and had a supporting part in the feature Rapture (1965).

In the mid-1960s, Stockwell dropped out of show business, becoming active in the Topanga Canyon hippie subculture as a close friend of visual artists George Herms and Wallace Berman, fellow child actor and "dropout" Russ Tamblyn, and musician Neil Young.

He guest starred on Thirty-Minute Theatre in Britain, The FBI, and Bonanza, and played the lead in AIP's The Dunwich Horror (1970) with Sandra Dee.

[23][26] He continued to guest for TV shows such as Police Surgeon, The Streets of San Francisco, Columbo, Joe Forrester, Three for the Road, Cannon, Ellery Queen, Police Story, McCloud, Tales of the Unexpected, Greatest Heroes of the Bible, Hart to Hart, The A Team, and Simon & Simon.

By this time Stockwell had moved to Taos, New Mexico, and was depressed about the state of his career, turning to real estate to pay the bills.

He was in episodes of Hunter and Murder, She Wrote, and the films Gardens of Stone (1987) (directed by Francis Ford Coppola), Beverly Hills Cop II (1987), Kenny Rogers as The Gambler, Part III: The Legend Continues (1987), The Time Guardian (1987), Banzai Runner (1987), and The Blue Iguana (1987).

In 1988, he was nominated for an Academy Award for Best Supporting Actor for his performance as Mafia boss Tony "the Tiger" Russo in the comedy Married to the Mob.

"[25] He also had roles in Tucker: The Man and His Dream (1988) from Coppola, Smokescreen (1988), the Brazilian The Long Haul (1989), the reboot of The Twilight Zone, Buying Time (1989), and Limit Up (1989).

Following the end of Quantum Leap, Stockwell appeared in Bonanza: The Return (1993), Caught in the Act (1993), In the Line of Duty: The Price of Vengeance (1994), Chasers (1994), Vanishing Son II (1994), Justice in a Small Town (1994), The Innocent (1994), Madonna: Innocence Lost (1994), Deadline for Murder: From the Files of Edna Buchanan (1995), and The Langoliers (1995).

Stockwell was in episodes of Snowy River: The McGregor Saga, Nowhere Man, The Commish, Can't Hurry Love, and Ink.

He had roles in the comedy Mr. Wrong (1996), Naked Souls (1996), Twilight Man (1996), Unabomber: The True Story (1996), Last Resort (1996), Close to Danger (1997), Living in Peril (1997), McHale's Navy (1997), Midnight Blue (1997), Air Force One (1997), The Shadow Men (1997), The Rainmaker (1997), and Sinbad: The Battle of the Dark Knights (1998).

Stockwell's performances in the 2000s included They Nest (2000), In Pursuit (2000), Batman Beyond: Return of the Joker (2000), The Flunky (2000), Italian Ties (2001), CQ (2001) directed by Coppola's son Roman, The Quickie (2001), Buffalo Soldiers (2001), Inferno (2002), The Manchurian Candidate (2004), The Deal (2007), and The Nanny Express (2008).