Her daughter, Phoebe Alexiades, says Canfield died of lung cancer on Saturday at a hospice in the California coastal town of Santa Barbara.
Canfield had appearances on a number of TV shows during a four-decade career, including General Hospital and The Hathaways.
She was Harriet Kravitz on four episodes of the 1960s series Bewitched.
But she was best known for her role of Ralph Monroe in some 40 episodes of "Green Acres," which ran from 1965 to 1971 and starred Eddie Albert and Eva Gabor.
Monroe greeted folks in the town of Hooterville with a cheery "howdy doody," wore painters' overalls and was forever working on the Douglas family's bedroom with her brother, Alf (Sid Melton).