Mariclare Catherine Costello (February 3, 1936 – April 17, 2026) was an American actress. She was a lifetime member of The Actors Studio. Costello's most notable role was that of Rosemary Hunter Fordwick on the television series The Waltons, from 1972 to 1977. In 1977, after her role on The Waltons, she played matriarch Maggie Fitzpatrick on the short-lived drama show The Fitzpatricks.
as Kathy Patterson
as Mother Mary Catherine(1 ep)
as David's Mother
as Susan Finn
as Rose
as Mary Alice Duncan
as Ellen Mancini
as Jane Bladow
as Cassie Latham Burns(1 ep)
as Senator Cunningham
as Adele Cooney (segment "The Bishop of Battle")
as Barbara Thompson
as Emma Spencer
as Audrey
as Winnie Naponic
as Louise Carpenter
as Anita Boyer(1 ep)
as Kay Wallace(1 ep)
as Louise Larsen(1 ep)
as Maggie Fitzpatrick(13 eps)
as Pat Morris
as Gabrielle Krieger
as Julia Baker
as Mrs. Warnall
as Louise
as Beryl Strauss
as Antoinette Slovik
as Diane Gordon(1 ep)
as Herself - Narrator
as Mrs. Rosemary Fordwick(4 eps)
as Miss Rosemary Hunter(3 eps)
as Mrs. Rosemary Fordwick (archive footage)(1 ep)
as Emily
as Honky Killer's Wife
