Martha Fernandez Miranda de Batista outlived her much older husband by 33 years. In recent years she had suffered from Alzheimer's disease, the Palm Beach Post reported.
Batista had already won and lost the Cuban presidency once when he married for the second time. The couple moved to the United States soon after.
In 1952, Batista returned to power in a coup. But as Castro approached Havana on New Year's Eve, 1958, Batista, his family and top members of the government fled the country in three planes, allegedly taking a fortune in looted cash and art.
Barred from the United States, the couple settled in Spain. After Batista's death, his widow moved to Florida, where she lived quietly in a Palm Beach mansion, giving large sums to medical charities.
"She was very private, almost reclusive, after my father died," her son, Robert, told the Post. "She had a gift for charity, but she did it very privately."
Mrs. Batista is to be buried in Madrid after a funeral in Florida. She is survived by three sons and a daughter. One son, Carlos, died of leukemia.