

Acting
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.
Highest rated appearances
as Emily
Appearances
as Rose

American Harvest
as Mary Alice Duncan

Heart of a Champion: The Ray Mancini Story
as Ellen Mancini

Victims for Victims: The Theresa Saldana Story
as Jane Bladow

The Adventures of Buckaroo Banzai Across the 8th Dimension
as Senator Cunningham

Nightmares
as Adele Cooney (segment "The Bishop of Battle")

Skeezer
as Barbara Thompson

Coward of the County
as Emma Spencer

Ordinary People
as Audrey

All God's Children
as Winnie Naponic

The Boy Who Drank Too Much
as Louise Carpenter

A Sensitive, Passionate Man
as Pat Morris

Raid on Entebbe
as Gabrielle Krieger

Territorial Men
as Julia Baker

Conspiracy of Terror
as Mrs. Warnall

After the Fall
as Louise

The Gun
as Beryl Strauss

The Execution of Private Slovik
as Antoinette Slovik

Going Where I've Never Been: The Photography of Diane Arbus
as Herself - Narrator

Let's Scare Jessica to Death
as Emily

Pound
as Honky Killer's Wife