Dick Guttman, a publicist for Mr. Landau, told the Associated Press the actor died of ‘‘unexpected complications’’ but did not provide details.
Mr. Landau’s seven-decade career featured verdant artistic peaks — including his work for directors Alfred Hitchcock, Francis Ford Coppola, Woody Allen and Tim Burton — and long stretches of arid desert.
The New Yorker once described him as ‘‘a survivor of B-movie hell,’’ noting his long midcareer run of disaster films, blaxploitation movies, and fright flicks. ‘‘None of them were porno,’’ the actor once quipped, ‘‘though some were worse.’’
A precociously gifted artist, Mr. Landau had been a cartoonist, illustrator, and theater caricaturist at the New York Daily News in his teens before embarking on an acting career at 22. He had developed a strong talent for observing people’s expressions and movements, as well as a flair for imitations and accents. Of thousands of applicants, only he and Steve McQueen were accepted in that class at the prestigious Actors Studio in Manhattan.
The school employed the Method philosophy, which calls on a performer to draw from his own often painful memories to illuminate a character. The system helped mold a generation of brooding stars, including Marlon Brando and James Dean. The 6-foot-3 Mr. Landau distinguished himself with a more subtle charisma and command of his craft, emerging as a versatile journeyman TV actor in the 1950s and 1960s.
Hitchcock, an early admirer, cast him in his most memorable early role, as espionage ringleader James Mason’s closeted gay minion Leonard in ‘‘North by Northwest’’ (1959). The film starred Cary Grant as a New York adman ensnared in an international spy ring.
Mr. Landau had proposed making Leonard covertly gay and worked with screenwriter Ernest Lehman to craft a line about his ‘‘woman’s intuition’’ — to be delivered before the character demonstrates how Mason’s girlfriend (played by Eva Marie Saint) has betrayed them.
‘‘It was quite a big risk in cinema at the time,’’ Mr. Landau told the London Daily Telegraph in 2012. ‘‘My logic was simply that he wanted to get rid of Eva Marie Saint with such a vengeance, so it made sense for him to be in love with his boss, Vandamm . . . Every one of my friends thought I was crazy, but Hitchcock liked it.’’
Mr. Landau became a full-fledged star in 1966 with ‘‘Mission: Impossible,’’ the CBS spy drama about an elite squad of government agents who infiltrate and destroy Cold War enemies. The cast included Steven Hill and later Peter Graves as the group’s boss and Barbara Bain, then Mr. Landau’s wife, as the sultry team member Cinnamon Carter. Lalo Schifrin’s pulse-quickening jazzy score and the self-destructing instructions that set every episode in motion helped make the program a popular success (as well as a target for parody).
Mr. Landau and his wife left the show — he quit in a salary dispute and she was fired in retaliation — three years into the show, at the peak of their fame. ‘‘Mission: Impossible’’ ran another four years without them. Mr. Landau said he found himself adrift, reduced to playing heavies in low-budget dreck. A nadir was the TV film ‘‘The Harlem Globetrotters on Gilligan’s Island’’ (1981).
His career was salvaged by Coppola, who cast Mr. Landau as an amiable elderly businessman with a huckster streak in ‘‘Tucker: The Man and His Dream’’ (1988). The film starred Jeff Bridges in the real-life story of industrialist Preston Tucker, who mounts a star-crossed attempt to challenge the Big Three automakers with a new car. Mr. Landau, almost unrecognizable with aging makeup and a mustache, played Tucker’s partner. He received a supporting Oscar nomination for his touching and understated performance, the start of an acting renaissance in his 60s.
A second Oscar nomination followed for Allen’s ‘‘Crimes and Misdemeanors’’ (1989), in which Mr. Landau brought a sympathetic twist to an ophthalmologist and philanthropist who is also an embezzler and arranges to have his mistress (Anjelica Huston) killed.
He received the Academy Award for Burton’s ‘‘Ed Wood’’ (1994), in which he had an impassioned supporting turn as the heroin-addicted, aging horror-film actor Bela Lugosi. Critics lauded the tragicomic poignancy Mr. Landau brought to the role of a once-big star reduced to appearing in movies directed by the bizarrely inept Wood.
A highlight was his Emmy Award-nominated role on the HBO comedy series ‘‘Entourage’’ as a washed-up Hollywood producer.
Mr. Landau was born in Brooklyn. He joined the Daily News in high school and after five years turned down a promotion. Seeing bad actors had persuaded him he could do better. ‘‘I told the picture editor I was going into the theater,’’ he told the Los Angeles Times. ‘‘I think he thought I was going to be an usher.’’