Lee Rich, the creative force behind Lorimar Productions, an independent studio that spawned two of television’s most enduring (and archetypally opposite) fictional American families — the poor but happy kinfolk of “The Waltons” and the rich but tortured Ewing clan of “Dallas” — died on Thursday in Los Angeles. He was 93.


His death was confirmed by his ex-wife, the actress Pippa Scott, with whom he remained close.


Mr. Rich founded Lorimar Productions in 1969 with a business partner, Merv Adelson, after nearly two decades on the advertiser side of the television business.


He was an executive with the ad agency Benton & Bowles in the 1950s and ’60s, a time when sponsors often became involved in the financing and even casting of shows, a business model carried over from the golden age of radio. In that quasi-producer’s role, Mr. Rich represented major advertisers like Procter & Gamble and Philip Morris in bringing a raft of prime-time shows to the air, including “Make Room for Daddy,” “The Dick Van Dyke Show,” “The Andy Griffith Show” and “Gomer Pyle, U.S.M.C.,” as well as the daytime soap operas “Guiding Light” and “The Edge of Night.”


When advertisers became less involved in television production, Mr. Rich told The New York Times in 1980, he decided to start a company of his own that would allow him to “do something pertinent and meaningful” in television and film. Between 1969 and 1986, Lorimar placed more than 30 shows on the air and produced a dozen feature-length films, including “Being There” (1979), “The Postman Always Rings Twice” (1981) and “An Officer and a Gentleman” (1982).


Besides “Dallas,” which ran for 13 seasons, and “The Waltons,” which was on the air from 1971 to 1981 and won 29 Emmy Awards, Lorimar’s most successful television productions included the series “Eight Is Enough,” “Falcon Crest” and the “Dallas” spinoff “Knots Landing,” and the made-for-TV movies “Helter Skelter” (1976), about the Charles Manson family, and “Sybil” (1976), starring Sally Field, about a woman with multiple personalities.


After leaving Lorimar in 1986, Mr. Rich became an executive for MGM/UA Communications. During his two years there he approved a number of scripts that became successful films, including “Moonstruck” (1987), “A Fish Called Wanda” (1988) and “Rain Man” (1988).


Lee Rich was born on Dec. 10, 1918, in Cleveland and raised in the suburb of Shaker Heights, Ohio, the older of two children. His father worked for a bank. He left for New York shortly after graduating from Ohio University with a degree in marketing. He sold handbags for a year, traveling up and down the East Coast, before talking his way into his first job in advertising, he said in 1999.


Besides Ms. Scott, his survivors include five children, Michael Henes, Jessica Rich, Miranda Tollman, Blair Rich and Anthony Rich.


In an extensive videotaped interview for the Archive of American Television in 1999, Mr. Rich presented a businesslike persona, devoid of artistic pretense. He was not a writer, he said; he just knew what worked on the small screen.


He had a hunch about “Dallas”: “I just felt that, if daytime serials could work, why couldn’t a nighttime serial work?” he said. An updated version of the series is scheduled to begin this month on the TNT cable network.


He described his role as a de facto enforcer of the Hollywood blacklist during the Red Scare of the 1950s with the same matter-of-factness:


“How did it work?” he said in answer to the interviewer’s question. “We had a list. There were certain people on it, and Procter & Gamble wouldn’t hire them.”


And “The Waltons,” he said, was clearly destined for success — “like God was looking down on us” — even after network executives first tried to convince him that it needed a star like Henry Fonda as the father. “So we showed the pilot to Henry Fonda,” he said, “and afterward he turned around to me and said: ‘What do you want me for? The family is the star. You don’t need me.’ ”


In an interview, Ms. Scott said Mr. Rich was a voracious reader, driven throughout his life by a hunger for stories. At the end of his life, when he was bedridden, he sometimes read two books a day, she said.


“He never stopped loving the great stories,” said Ms. Scott. “To Lee, ‘story’ was everything.”