Barbara Bel Geddes, 82, a veteran stage and film actress best known for her TV role as Miss Ellie, the likable, long-suffering matriarch of the rambunctious Ewing clan on "Dallas," died Aug. 8 of lung cancer at her home in Northeast Harbor, Maine.

The CBS prime-time soap opera debuted in 1978, and the romantic entanglements, wheeler-dealer scheming and intra-family feuding of the larger-than-life oil and ranching Texans quickly made it one of the most popular dramas in TV history.

Ms. Bel Geddes won an Emmy in 1980 as best lead actress in a series. Week in and week out, her Miss Ellie was the calm at the center of Southfork cyclones involving her grown children, the lubriciously amoral J.R. (Larry Hagman) and his little brother, Bobby (Patrick Duffy), and other members of the querulous extended clan. She left the show for six months in 1984 after having quadruple bypass heart surgery but returned when "Dallas" fans reacted negatively to Donna Reed as her replacement. She stayed with the series for five more years.

Her "Dallas" success came toward the end of her acting career. She had made her Broadway debut at 19 and had starred in plays written by the likes of Edward Albee, Tennessee Williams and Terence Rattigan. In Hollywood, she earned an Academy Award nomination for her role as Irene Dunne's daughter in "I Remember Mama" (1948) and played opposite James Stewart in Alfred Hitchcock's "Vertigo" (1958).

She was born Oct. 31, 1922, in New York City into a theatrical family. Her father was the noted theatrical and industrial designer Norman Bel Geddes.

Her parents divorced when she was 5, and she moved with her mother and older sister to Milburn, N.J. When she was 16, her mother died, and she was sent to Putney School in Vermont. She was dismissed from the school after she was discovered kissing a boy.

Although a Putney drama teacher had told her father that she had no acting talent, she made her stage debut at 18 in a summer-stock production of "The School for Scandal." She debuted on Broadway a year later as a flighty ingenue in the 1941 comedy "Out of the Frying Pan."

After touring with the USO during World War II, she was chosen by director Elia Kazan for the lead in the play "Deep Are the Roots" (1945), an interracial love story. She won a New York Drama Critics Award and the first Clarence Derwent Award as outstanding young actress of the year.

She made her film debut in 1947, playing opposite Henry Fonda in "The Long Night." Under contract to RKO Radio Studios, she also appeared in "Blood on the Moon" (1948), "Caught" (1949) and "Panic in the Streets" (1950). RKO fired her after studio chief Howard Hughes decided she wasn't sexy enough.

She had difficulty finding work in Hollywood after refusing to name names during testimony before the House Un-American Activities Committee. She returned to New York, where she appeared in the John Steinbeck play "Burning Bright" (1950) and in "The Moon Is Blue" (1951). In 1955, she originated the role of Maggie, the sexually starved wife in Williams's "Cat on a Hot Tin Roof." Her biggest success on Broadway was the Jean Kerr comedy "Mary, Mary," which opened in 1961 and ran for more than 1,500 performances.

Hitchcock brought her back to Hollywood for "Vertigo," in which she played Stewart's likable and level-headed girlfriend. The role was something of a stock Bel Geddes character, although in a 1958 episode of Hitchcock's weekly TV anthology, she played very much against type. She appeared as a lady who kills her philandering husband with a blunt object -- a frozen leg of lamb -- and then calmly serves the evidence to investigating detectives.

She retired in 1966 to care for her second husband, Broadway director Windsor Lewis, who died of cancer in 1972. She was "flat broke," she said, when "Dallas" came along. She did little acting after leaving "Dallas" in 1990.

Ms. Bel Geddes's first marriage, to Carl Schreuer, ended in divorce.

Survivors include a daughter from the first marriage and a daughter from the second.