Fernando Bermúdez (died 978), second Count of Cea, was the son of Bermudo Núñez and his wife Argilo. As the father of a queen of Navarre, and therefore, ancestor of many royal houses, Fernando was a distinguished member of the highest ranks of the nobility of the Kingdom of León.
The firstborn of count Bermudo Núñez, he inherited many properties from his father and also from his uncle Oveco Núñez, Bishop of León, and appears as Fredenando Vermudiz in a donation made on 28 August 945 by the bishop to the Monastery of Sahagún. The relationship is also confirmed in a charter dated 984 when it mentions that this monastery had acquired a certain property from count Fernando Bermúdez that had previously belonged to the bishop.
He spent his first years in Asturias where he had vast holdings, some of which had been donated by Queen Urraca, the widow of King Fruela II of Asturias, and by the Infantes Ramiro and Ordoño Froilaz, as attested in an inventory of various properties in Naptavlio that were probably given as compensation for his support of King Fruela and for having participated in the rebellion in 932 against King Ramiro II who forced Fernando to return two churches to the Cathedral of Oviedo. His relations with the crown improved during the reign of King Ordoño III. He was the mayordomo mayor of this king, confirmed many of his royal charters as an active member of the curia regis, and appears for the first time in 960 with the title of "Count". His last appearance in medieval charters was in 978.
He married Elvira Díaz, daughter of Diego Muñoz, count of Saldaña, and his wife Tregidia. They were the parents of: