Gilbert died of natural causes Saturday at a retirement community in the San Francisco Bay Area suburb of Mill Valley, said her longtime partner, Donna Korones.
With the Weavers, whose other members were Pete Seeger, Lee Hays and Fred Hellerman, Gilbert helped spark a national folk revival by churning out hit recordings of "Goodnight Irene," ''Tzena Tzena Tzena," ''On Top of Old Smokey," ''If I Had A Hammer," ''Kisses Sweeter Than Wine" and "Wimoweh."
The group was hugely popular before its left-wing activities were targeted by anti-Communists during the McCarthy era. They were blacklisted, unable to record, appear on television or radio and perform in many concert venues, and eventually disbanded.
Gilbert went on to pursue a solo career as a singer, as a stage actor and psychologist.
Gilbert's memoir, "Ronnie Gilbert: A Radical Life in Song," which is the same title of a one-woman show she performed for years, will be published in the fall.
She is survived by her daughter, Lisa, and Korones, her partner of 30 years.