MARICLARE COSTELLO, ACTRESS FROM THE WALTONS AND CULT HORROR FILM STAR OF LET’S SCARE JESSICA TO DEATH, DIES AT 90.(PHOTO).

Mariclare Costello, actress from The Waltons and cult horror film star of Let’s Scare Jessica to Death, dies at 90

Mariclare Costello, a veteran stage and screen actress and lifetime member of The Actors Studio, has died at the age of 90. She passed away on April 17 in Brooklyn, her family said.

Costello was widely recognized for her role as schoolteacher Rosemary Hunter on CBS’s The Waltons, where she appeared in 15 episodes during the series’s first five seasons from 1972 to 1977. Her character became a memorable part of Walton’s Mountain, including a storyline in which she married Rev. Matthew Fordwick, played by John Ritter. She also appeared in the series Sara during the same era.

In film, Costello earned a lasting cult following for her role as Emily Bishop in the 1971 horror film Let’s Scare Jessica to Death, where she portrayed a mysterious figure tied to a psychological and supernatural story. One of her most striking scenes featured her rising from a lake in a wedding dress.

Born in Peoria, Illinois, in 1936, Costello built an extensive theater career before moving into television and film. She was an original member of the Lincoln Center Repertory Company and performed in multiple Broadway productions, including a revival of Harvey alongside Jimmy Stewart and Helen Hayes. She also worked with major theater figures throughout her career and made her Broadway debut in the mid-1960s.

Her television work included appearances in Ironside, Kojak, Lou Grant, Murder, She Wrote, and Chicago Hope. She also appeared in films such as Ordinary People and The Adventures of Buckaroo Banzai Across the 8th Dimension.

Costello was married to actor Allan Arbus, known for MASH*, from 1977 until he died in 2013. The couple met through acting work and later settled in Los Angeles.

Beyond acting, she taught drama for many years at schools and universities in California and worked with theater programs focused on education and community outreach. Her family described her as deeply curious, creative, and energetic, noting her lifelong passion for teaching, storytelling, and hands-on creativity.

She is survived by her daughter Arin, granddaughter Bird, stepdaughters Amy and Doon, and several extended family members. A funeral service will be held in New York, with burial and remembrance planned in Peoria, Illinois.