Maria of Castile (14 September 1401 – 7 September 1458) was Queen consort of Aragon and Naples as the spouse of Alfonso V of Aragon.
Maria acted as the regent of Aragon during the reign of her spouse, as he was absent during most of his reign; her regencies lasted between 1420 and 1423 and between 1432 and 1458.
She was also briefly Princess of Asturias in her own right as the heir presumptive to the throne of Castile.