An attractive, accomplished actress, Martha Scott began her professional career appearing in Shakespearean productions at the 1933-34 Chicago World's Fair. After further honing her craft in stock and on radio, she made her mark as Emily in the 1938 original Broadway production of Thornton Wilder's Pulitzer-winning "Our Town". Scott earned a 1940 Best Supporting Actress Oscar nomination for her film debut recreating the stage role. For much of her early feature career, the Missouri native generally playing characters much older than herself like the titular elderly woman reflecting on her life in Tay Garnett's "Cheers for Miss Bishop" or her loyal parson's wife in "One Foot in Heaven" (both 1941). Scott delivered a strong portrait of a greedy harridan married to a selfless newspaper editor (John Mills) in "So Well Remembered" (1947). In "The Desperate Hours" (1955), she was stalwart as the wife and mother of the family held hostage by Humphrey Bogart. The actress played the mother of Charlton Heston (nine years her junior) in two 50s Biblical epics, Cecil B. DeMille's "The Ten Commandments" (1955) and William Wyler's Oscar-winner "Ben-Hur" (1959). After an absence of a decade and a half, Scott returned to acting as a nun on board a distressed plane in the schlocky sequel "Airport 1975" (1975) and offered an astringent turn as a ballet company manager in Herbert Ross' "The Turning Point" (1977).
Scott began appearing on the small screen in the early 50s in such anthology series as "The Web" and "Teller of Tales". She hosted and narrated "Modern Romances" (NBC, 1954-58). For much of the 60s, she concentrated on stage work, making occasional guest appearances on shows ranging from "The F.B.I." to "Columbo". When she became more active in the 70s, it was often in character roles. Scott had the recurring role of Bob's mother on "The Bob Newhart Show" and also appeared as the mother of Sue Ellen Ewing (Linda Gray) on "Dallas" in 1979 and 1985. In the short-lived primetime soap "Secrets of Midland Heights" (1980-81), she was the matriarch of a wealthy but morally bankrupt family. In a fascinating episode of "Murder, She Wrote" in 1987, Scott, Jeffrey Lynn and Harry Morgan reprised their screen roles in 1949's "Strange Bargain". The plot presumed to find the real killer and incorporated scenes from the original film.
In addition to acting, Scott had a secondary career as a producer with both the (1978) Broadway and (1991) film versions of "First Monday in October", a comedy drama about the first woman appointed to the Supreme Court. The former paired Henry Fonda and Jane Alexander, the latter Walter Matthau and Jill Clayburgh.