Mariclare Costello, Teacher Rosemary On ‘The Waltons’, Dies At 90

BusinessHollywood & EntertainmentMariclare Costello, Teacher Rosemary On ‘The Waltons’, Dies At 90ByTim Lammers,Contributor.Forbes contributors publish independent expert analyses and insights. I cover Hollywood and entertainment.Follow AuthorApr 27, 2026, 12:53pm EDTApr 27, 2026, 01:04pm EDT--:-- / --:--This voice experience is generated by AI. Learn more.This voice experience is generated by AI. Learn more.Mariclare Costello stands with her thumbs in her pockets in a scene from the film 'Let's Scare Jessica to Death', 1971. (Photo by Paramount Pictures/Getty Images)Getty ImagesMariclare Costello, a prolific actress whose credits include The Waltons and Let’s Scare Jessica to Death, has died.Costello died on April 17 in Brooklyn, N.Y., her family wrote on Legacy. She was 90.ForbesNedra Talley Ross, Last Surviving Ronettes Singer, Dies At 80By Tim LammersThe actress was born Mariclare Catherine Costello on Feb. 3, 1936, in Peoria, Ill. According to her family, Costello moved to New York after graduate school to pursue a career in theater, where she became a lifelong member of The Actors’ Studio.Costello’s screen debut came in a small supporting role in Arthur Hiller’s 1967 comedy The Tiger Makes Out, starring Eli Wallach and Anne Jackson.Mariclare Costello stands on the staircase as she talks with Kevin O'Connor in a scene from the film 'Let's Scare Jessica To Death', 1971. (Photo by Paramount Pictures/Getty Images)Getty ImagesIn 1971, Costello landed the role of Emily, a mysterious drifter believed to be a vampire by a mentally fragile Jessica (Zohra Lampert) in the psychological horror film classic Let’s Scare Jessica to Death.MORE FOR YOUOn television, Costello played the recurring role of schoolteacher Rosemary Hunter on The Waltons, appearing in 15 episodes over five seasons of the classic TV drama from 1972-1977.ForbesDave Mason, ‘We Just Disagree’ Singer And Traffic Co-Founder, Dies At 79By Tim LammersIn 1977, Costello m...