Hermenegildo Gutiérrez (Hermenegildo Guterres in Portuguese) (c. 850 – after May 912), was a distinguished Galician noble who lived during the 9th and 10th centuries. As the Mayordomo mayor of King Alfonso III, he was an active member of the curia regia. His daughter Elvira, as the first wife of King Ordoño II, was queen consort of León.
Count Hermenegildo, the son of count Gutierre and his wife Elvira, appears in medieval documentation starting in 869 — when with his father-in-law, Gatón, count in Astorga and El Bierzo, settled a dispute between the king of Asturias and bishop Mauro — until his last appearance in May 912, when he confirmed a donation made by his son-in-law, king Ordoño II, to the Cathedral of Santiago de Compostela. He was one of the most loyal vassals of King Alfonso III, who named him his mayordomo mayor and compensated his efforts and services to the crown with many properties and tenencias.
Hermenegildo played an active role in military operations during the Reconquista. In 878, he defeated the Muslim troops who had attacked Oporto and then Coimbra, repopulating these cities, as well as neighboring Braga, Viseu, and Lamego, with people from Galicia after expelling the Moors. His holdings there would pass to his descendants and come to be called the County of Coimbra, which was retaken again in 987 by Almanzor and it was not until 1064 that the city was permanently reconquered by the Christian armies of Ferdinand I of León.