Dean Stockwell was born Robert Dean Stockwell in North Hollywood, Los Angeles, California, the younger son of Nina Olivette, an actress and dancer, and Harry Stockwell, an actor and singer. His elder brother was actor Guy Stockwell.
In 1945, he appeared in a main character role (Donald Martin) in the musical movie Anchors Aweighalongside Frank Sinatra and Gene Kelly. Some of his other notable child roles included that of Robert Shannon in The Green Years (1946), Gregory Peck's son in Gentleman's Agreement (1947), as the son of William Powell and Myrna Loy as Nick and Nora Charles, Nick Jr., in Song of the Thin Man (1947), and as Lionel Barrymore's grandson and Richard Widmark's protege in Down to the Sea in Ships (1949). He also starred in the lead role of the film The Boy with Green Hair in 1948, and in a film adaptation of The Secret Garden in 1949. In 1950, he appeared in a lead role alongside Errol Flynn in Kim, the film of Rudyard Kipling's novel of the same name.
Unlike many child actors, he continued to act past his teenage years. In 1957, he starred as Judd Steiner in the Broadway adaptation ofCompulsion, based on the Leopold and Loeb story; he played the same role in the 1959 film adaptation Compulsion. Compulsion also starredBradford Dillman and Orson Welles as the Clarence Darrow-based lawyer Jonathan Wilk. In 1958, he joined Gloria Talbott and Dan Blocker as guest stars in the episode "Mercyday" of the NBC western series The Restless Gun, starring John Payne.
In 1960, he played coal miner's son Paul Morel in the British film Sons and Lovers, an American actor cast as an Englishman, working alongside Trevor Howard and Wendy Hiller. In 1961, Stockwell appeared in the premiere episode of ABC's Bus Stop series, which starred Marilyn Maxwell. In 1962, he appeared in an adaptation of Eugene O'Neill's play Long Day's Journey Into Night along with Katharine Hepburn, Ralph Richardson and Jason Robards. In 1964, Stockwell guest-starred in an episode of NBC's medical drama The Eleventh Hour.
In the early 1960s, Stockwell dropped out of show business, becoming active in the hippie subculture.
Stockwell appeared in a 1969 episode of Bonanza as a down-and-out former Union soldier. He then appeared in two episodes of the mystery series Columbo. In 1973, he was the leading actor in a horror B-film called The Werewolf of Washington. Stockwell played Jack Whittier, a reporter who had an affair with the daughter of the U.S. President and is sent to Hungary. There he is bitten by a werewolf, and then gets transferred back to Washington, D.C., where he gets a job as the press secretary to the President. During the mid-1970s Stockwell worked as a real-estate broker.
In 1984, he appeared in Wim Wenders' critically acclaimed film Paris, Texas, and in that same year, in David Lynch's film version of Dune as Wellington Yueh. The following year he turned in a brief but significant role as attorney Bob Grimes in William Friedkin's To Live and Die in L.A. In 1986, Stockwell made an appearance in another Lynch production, the neo-noir thriller Blue Velvet. 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. He received a star on the Hollywood Walk of Fame on February 29, 1992 (Leap Day) following the success of Quantum Leap.
Along with Jack Lemmon and Marcello Mastroianni, Stockwell won the award for best actor at the Cannes Film Festival twice, for Compulsion and Long Day's Journey Into Night.
Stockwell joined the cast of Battlestar Galactica starting with its second season finale, portraying what became the lead antagonist, Cylon John Cavil.
Stockwell married actress Millie Perkins in 1960 and the two divorced in 1962. In 1981 he married Joy Marchenko, with whom he had two children; they divorced in 2004.
Stockwell has been widely reported to be the godfather of actress Amber Tamblyn; however, in a 2009 interview with Parade Magazine, Tamblyn explained that Stockwell was one of three famous friends of her father, actor Russ Tamblyn, who were always around the house when she was growing up, and who were big influences on her life. The other two, in addition to Stockwell, were actor Dennis Hopper, and musician Neil Young. The word "godfather" was "just a loose term I’ve always used for all of them," Tamblyn explained in the interview, suggesting that Stockwell's "godfather" moniker is informal, at best.
Stockwell is an accomplished artist who creates both digitally enhanced photographs and original collages in the style of his friend and fellow artist, Wallace Berman. During his time at the University of California, Berkeley, Stockwell immersed himself in music and wrote several small compositions. As part of his friendship with musician Neil Young, Stockwell designed the album cover art for American Stars 'N Bars. Together, they directed Human Highway, which Stockwell also co-wrote. The title track from Young's 1970 album After the Gold Rush is based on the title of a screenplay written by Stockwell.
Stockwell is an avid golfer and would play golf during breaks in filming episodes of Quantum Leap. He's a martial artist, holding instructor rank in Modern Arnis.