Alfonso Enríquez (Gijón, 1355 – Marans or Portugal, c. 1400), Count of Noreña and of Gijón and lord of several places, was the eldest son of King Henry II of Castile and Elvira Íñiguez born before the king's marriage. As one of the most powerful feudal lords in Asturias, where he owned many properties, he attempted to declare the independence of this region from his brother King John I and then from his nephew, King Henry III of Castile. He and his Portuguese wife, Isabel of Portugal, a natural daughter of King Ferdinand I, are the ancestors of the Noronha lineage in Portugal.