Carlotta Mercedes McCambridge was an American actress. Orson Welles called her "the world's greatest living radio actress."
McCambridge was born in Joliet, Illinois, the daughter of Irish American Catholic parents Marie and John Patrick McCambridge. She graduated from Mundelein College in Chicago before embarking on a career.
She began her career as a radio actor during the 1940s while also performing on Broadway. Her radio work in this period included her portrayal of Rosemary Levy on Abie's Irish Rose and various characters on the radio series I Love A Mystery in both its West Coast and East Coast incarnations. She frequently did feature roles on the CBS Radio Mystery Theater, and was an original cast member on The Guiding Light, before the Bauers took over as the central characters. She also starred in her own show, The Defense Attorney as Martha Ellis Bryant.
Her Hollywood break came when she was cast opposite Broderick Crawford in the 1949 film All the King's Men. McCambridge won the 1949 Academy Award for Best Supporting Actress for her role in the film, which won Best Picture for that year. McCambridge also won the Golden Globe Awards for Best Supporting Actress and New Star of the Year - Actress for her performance.