Fickett, who won an Emmy for her portrayal of nurse Ruth Martin, was an original castmember on the ABC soap, which premiered in 1970. Fickett retired from All My Children in 2000.
"We at ABC were very saddened to learn about the passing of one of All My Children's original cast members," the network said in a statement. "As we honor All My Children's 41 years on ABC, we cannot help but recognize and remember Mary's wonderful depiction of Pine Valley's revered Ruth. Ruth's marriage to chief of staff Dr. Joe Martin provided the bedrock upon which the town of Pine Valley was built. Their marriage was always a stabilizing force that represented 'home' for many."
Fickett is survived by a daughter, a son, grandchildren and great-grandchildren.
ABC plans to dedicate the Wednesday, Sept. 21 episode to Fickett. The final episode of All My Children on daytime airs two days later.