Mariclare Costello, a versatile actor known for her role as the compassionate schoolteacher Rosemary Hunter on The Waltons and for her striking performance in the 1971 cult horror film Let’s Scare Jessica to Death, passed away on Friday, April 17, in Brooklyn. She was 90 years old, her family confirmed.
Costello built a rich and varied career across stage, film, and television. She appeared in nine Broadway productions during the 1960s and was deeply rooted in the theater world.
A graduate of Catholic University, where she earned a master’s degree in theater and education, she later became an original member of the Lincoln Center Repertory Company and a lifetime member of The Actors Studio.
Born on February 3, 1936, in Peoria, Illinois, Costello moved to New York City after completing her studies and quickly established herself on both Off-Broadway and Broadway stages.
Her Broadway debut came in 1964 in Arthur Miller’s After the Fall, where she performed alongside Jason Robards.
She went on to appear in several notable productions, including Tartuffe, Danton’s Death, The Country Wife, Lovers and Other Strangers, A Patriot for Me, and Harvey, the latter featuring James Stewart and Helen Hayes.
Her screen career began with the 1967 film The Tiger Makes Out, followed by guest roles on television series such as N.Y.P.D..
In 1971, she gained wider recognition for her haunting role in Let’s Scare Jessica to Death, portraying a mysterious hippie who ultimately reveals herself as a vampire.
One of the film’s most memorable moments features her eerie emergence from a lake, a scene that cemented her place in cult horror history.
Costello continued to work steadily in film and television. She appeared in the acclaimed 1974 TV movie The Execution of Private Slovik and later in Ordinary People (1980), where she played a supportive sister-in-law to Mary Tyler Moore’s grieving character.
Over the years, she made guest appearances in numerous popular TV series, including Ironside, Kojak, Little House on the Prairie, Lou Grant, Murder, She Wrote, Chicago Hope, and Judging Amy, among others.
Although she had a regular role in the short-lived 1977 drama The Fitzpatricks, Costello remained best known to many viewers for her recurring role on The Waltons.
Appearing over five seasons from 1972 to 1977, she portrayed Miss Rosemary Hunter, a nurturing teacher who inspires a young John-Boy Walton to pursue writing. Her character later marries the town’s minister.
Costello was married to actor Allan Arbus until his death in 2013. She is survived by her daughter, stage director Arin Arbus; Arin’s partner, playwright Ethan Lipton; her granddaughter, Bird; stepdaughters Amy and Doon; as well as several nieces and a nephew.
A funeral service will take place in New York City, with burial and a memorial planned in her hometown of Peoria, Illinois.
