Agnes Moorehead was born of Anglo-Irish ancestry near Boston, the daughter of a Presbyterian minister and a mezzo-soprano who encouraged her to perform in church pageants. At the age of three, she sang "The Lord is my Shepherd" on a public stage, and seven years later, she joined the St. Louis Municipal Opera as a dancer and singer.
She attended Muskingum College in Ohio and the University of Wisconsin, graduating with an M.A. in English and public speaking and later adding a doctorate in literature from Bradley University. She taught public school English and drama for five years before moving to Paris to study pantomime with Marcel Marceau.
In 1928, she began training at the American Academy for Dramatic Arts and graduated with honors the following year. She started her radio career in 1923 as a singer for a St. Louis radio station and went on to appear in numerous serials, dramas, and children's programs. She was Min Gump in "The Gumps" and the "dragon lady" in "Terry and the Pirates," among other roles.
Agnes met Orson Welles through her radio work and joined his Mercury Theatre on the Air, participating in the famous "War of the Worlds" broadcast of 1938. She then went on to join RKO in Hollywood, where she received a lucrative contract.
As a character actress, Agnes was impossible to typecast, playing years older than her age, heroine or villainess, tragedienne or comedienne. She received critical acclaim for her roles in "Citizen Kane" and "The Magnificent Ambersons," and was nominated for an Academy Award for her performance in the latter.
Agnes appeared in numerous films, including "Jane Eyre," "The Woman in White," "The Lost Moment," and "Dark Passage," as well as starring in the campy horror flick "The Bat." She also had a successful career on Broadway, appearing in plays such as "All the King's Men" and "Candlelight."
Agnes toured nationally with her one-woman show "The Fabulous Redhead" and performed numerous times on television before landing the role of Endora on "Bewitched." She also starred in the starring role in "The Invaders," a television film where she played a lonely old woman confronted by tiny alien invaders in her remote farmhouse.
Despite being immortalized as Elizabeth Montgomery's flamboyant witch-mother, Agnes Moorehead was not pleased with this role and had a special clause inserted in her contract limiting her appearances to eight out of twelve episodes.