Mirta Díaz-Balart nació el 30 de septiembre de 1928 en La Habana, Cuba. Estuvo casada con Emilio Núñez Blanco, Fidel Castro y Emilio Núñez Portuondo. Murió el 6 de julio de 2024 en Madrid, España.
She met Fidel Castro while she was studying philosophy and literature at the University of Havana; he was studying law. Eventually, Castro became an enemy of the Bastista regime, as well as Batista's allies such as Ms. Díaz-Balart's family. She was caught in the middle.