Isabel of Barcelos (October 1402 – 26 October 1466), also known as Isabel of Braganza (her father was originally the Count of Barcelos before becoming Duke of Braganza). She was the daughter of Afonso I, Duke of Braganza and Beatriz Pereira de Alvim, she married Infante John, Lord of Reguengos de Monsaraz, her half-uncle, son of John I of Portugal.