Carlotta Mercedes Agnes McCambridge (March 16, 1916 – March 2, 2004) was an American actress of radio, stage, film, and television. Orson Welles called her "the world's greatest living radio actress". She won an Academy Award for Best Supporting Actress for her screen debut in All the King's Men (1949) and was nominated in the same category for Giant (1956). She voiced the majority of dialogue for demon Pazuzu in The Exorcist (1973).

McCambridge began her career as a radio actor during the 1930s while also performing on Broadway. In 1941, she played Judy's friend in A Date with Judy. She had the title role in Defense Attorney, a crime drama broadcast on ABC in 1951–52.