Sarah Marshall, an actress who was born into show business and worked on Broadway, in film and on television, perhaps most memorably in episodes of “The Twilight Zone” and “Star Trek,” died on Jan. 18 at her home in Los Angeles. She was 80.

The cause was stomach cancer, said her grandson, Seamus Marshall Bourne.

Ms. Marshall was the only daughter of the British film and theater stars Herbert Marshall and Edna Best. She left private school at 16 to pursue acting full time, with her mother’s help.

“We decided acting was a better education than school,” she was quoted as saying in Sidney Fields’s syndicated column “Only Human” in 1958. She was often cast as an ingénue.