Mariclare Costello, best known to The Waltons fans as the warm and memorable teacher Rosemary Hunter, has died at the age of 90.
“Her gift was rare,” her family wrote in an obituary.
“She knew how to help people get out of their own heads, focus on a task rather than themselves, and in doing so, helped them access their own creative voices.”
According to the obituary, published in the Peoria Journal Star, she passed away on the morning of Friday, April 17, in Brooklyn, New York.
For many viewers, Costello will always be remembered as part of the heart of The Waltons — a series known for its warmth, family values, and deeply human storytelling. She played Miss Hunter, the local schoolteacher.
Her presence on the show left a lasting impression during its early seasons, when her character became a quiet but meaningful part of the community on Walton’s Mountain.
In a 2011 interview, Costello reflected fondly on her time with the cast.
“I had the greatest time with Richard Thomas and John Ritter. We laughed from the beginning of the day until the end of the day. We spent a lot of time together. They were great,” she said.
A Midwesterner by birth and a vegetarian by choice, her career extended far beyond Walton’s Mountain.
She was born in Peoria, Illinois, and grew up in a stable, middle-class family with a creative spirit. Her father worked as a bridge designer for the state, and she was encouraged to explore the arts from an early age. That journey eventually led her to study theater and education, where she earned a master’s degree in drama and began building the foundation for a long career on stage and screen.
She even performed for President John F. Kennedy in a production of The Merchant of Venice.
From New York stages to Broadway productions, she built a respected theater career before moving into film and television in the late 1960s.
Her screen work included appearances in acclaimed projects such as Ordinary People and the cult horror favorite Let’s Scare Jessica to Death, along with guest roles on some of television’s most beloved series.
Off screen, she was remembered just as warmly.
“Her gift was rare,” her family wrote. “She was a wonderful cook, she loved rescuing stray animals, and she had a way of making every space she entered more beautiful.”
“She was also, in every part of her life, someone who paid attention,” they added. “She could talk to anyone, was interested in everything, and was a relentless asker of questions.”
She was married to actor Allan Arbus, known for MASH, from 1977 until his death in 2013. Together, they shared a life in Los Angeles filled with art, teaching, and creativity. Arbus died of congestive heart failure in 2013 at the age of 95.
Mariclare Costello is survived by her daughter Arin, granddaughter Bird, stepdaughters Amy and Doon, and extended family who remember her as deeply curious, endlessly warm, and full of life.
For The Waltons audience, she remains part of a television world built on heart — and a reminder of the quiet performers who helped make it unforgettable.
