John Forsythe, the debonair actor whose matinee-idol looks, confident charm and mellifluous voice helped make him the star of three hit television series, including ABC’s glamour soap “Dynasty,” died on Thursday at his home in Santa Ynez, Calif. He was 92.

His publicist, B. Harlan Boll, said the cause was complications of pneumonia, following a yearlong battle with cancer. Mr. Forsythe had earlier received a diagnosis of colon cancer, and in 1979 underwent quadruple bypass surgery.

Mr. Forsythe may be best remembered as Blake Carrington, the dapper, silver-haired but ruthless Denver oil tycoon on “Dynasty,” which ran from 1981 to 1989 and took its place as a symbol of the affluent decade of the Reagan administration. He often expressed amusement that the role, as the object of two women’s fierce affection — that of Joan Collins and Linda Evans — had made him a sex symbol in his 60s.

His first leader character in a series was another dashing, well-dressed, self-possessed man of means: Bentley Gregg, the playboy Beverly Hills lawyer in the sitcom “Bachelor Father” (1957-62). Gregg was bringing up his teenage niece (Noreen Corcoran), whose parents had died in an accident.

Between those two series, Mr. Forsythe played a crucial role in “Charlie’s Angels” (1976-81), the hit show about three young, attractive female detectives, originally played by Kate Jackson, Jaclyn Smith and Farrah Fawcett. Mr. Forsythe’s part was as the sexy telephone voice of their boss, a millionaire private eye who had others handle his cases.

His role in “Dynasty” brought him four Golden Globe award nominations and two Golden Globes as well as three Emmy Award nominations.

Mr. Forsythe was often endearingly forthright with interviewers. In 1981 he told The Associated Press: “I figure there are a few actors like Marlon Brando, George C. Scott and Laurence Olivier who have been touched by the hand of God. I’m in the next bunch.”

Another time, speaking of a fictional nation featured in the later seasons of “Dynasty,” he said: “Moldavia — we’re still living that down. That was one of our less effective story lines.”

It was certainly one of their most preposterous. The story hit its peak with a season finale in which revolutionaries barged into a royal wedding with machine guns blazing; half the glamorous cast were left for dead until fall.

John Lincoln Freund was born on Jan. 29, 1918, in Penns Grove, N.J. His family later moved to New York City, where his father was a stockbroker and where John graduated from Abraham Lincoln High School in Brooklyn.

He attended the University of North Carolina at Chapel Hill but dropped out after three years because of a particularly successful summer job as an announcer for the Brooklyn Dodgers at Ebbets Field. People liked his voice so much that he easily moved into radio acting.

Mr. Forsythe made his stage and film debuts in the early 1940s. In 1942 he appeared on the New York stage in a supporting role as a coastguardsman in “Yankee Point,” a home-front drama. His first credited movie appearance was as a sailor in “Destination Tokyo” (1943), starring Cary Grant. That same year he was in the ensemble of “Winged Victory,” Moss Hart’s Broadway tribute to the United States Army Air Forces, the military’s aviation branch during World War II, in which Mr. Forsythe served.

Beginning in 1948, Mr. Forsythe did guest appearances on dozens of television series. Twice in the early 1950s he played a newspaper editor, in “The Captive City” (1952) and “It Happens Every Thursday” (1953).

He was back in a military uniform for his big Broadway break, playing a bumbling American officer in occupied Japan in “The Teahouse of the August Moon” (1953). Brooks Atkinson, writing in The New York Times, called Mr. Forsythe “as perfect in the part of the captain as Henry Fonda was in ‘Mister Roberts.’ ”

Mr. Forsythe did several Broadway shows, including replacing Henry Fonda in “Mister Roberts,” and was an original member of the Actors Studio, New York’s bastion of Method acting. But for the sake of his family, he chose the security of television.

“I’ve had a good time,” he told The Globe and Mail, the Toronto newspaper, in 1984. “But if I had been willing to starve so that I could play Hamlet, I might have been a better actor than I am today.”

Like many television regulars, he had his share of less successful network ventures. They included three sitcoms: “The John Forsythe Show,” in which he played an Air Force major running a girls’ school (it lasted one season, 1965-66); “To Rome With Love,” about a widowed professor living in Italy (1969-71); and “The Powers That Be,” about a clueless United States senator whose life is run by others. It ran for 21 episodes (1992-93), possibly because viewers weren’t interested in seeing a clueless John Forsythe.

One of his finest television roles was outside the series format. He starred as the theater critic Al Manheim in the acclaimed 1959 television film “What Makes Sammy Run?”

His film career covered various genres. He played a helpful artist in Alfred Hitchcock’s comic mystery “The Trouble With Harry” (1955); a wealthy political type in “Kitten With a Whip” (1964), a crime drama with Ann-Margret; the rich man whose family makes his young wife disappear in “Madame X” (1966); and the chief murder investigator in “In Cold Blood” (1967).

His last full-fledged major film appearance was in the 1988 holiday comedy “Scrooged.” He played a contemporary Marley’s Ghost, returning from the dead in rotting golf clothes.

Mr. Forsythe’s voice was heard, however, in the 2000 “Charlie’s Angels” film and its 2003 sequel. His last television appearance was in May 2006, participating in a “Dynasty” cast reunion.

Mr. Forsythe was briefly married to Parker McCormick, with whom he had a son. The year of their divorce, he married Julie Warren. They had two daughters and were together, for more than 50 years, until her death in 1994. Nicole Carter became his third wife in 2002 and survives him.

He is also survived by his son, Dall; his daughters, Page Courtemanche and Brooke Forsythe, all of Southern California; six grandchildren; and five great-grandchildren.

“I always said life consists of love and work,” Mr. Forsythe told a writer for TV Guide not long after his second wife’s death. “I tried to balance it 50-50. And, of course, now I’m so happy I did.”