Bermudo Ovéquiz (fl. 1044–1092) (also known as Vermudo) was a member of the highest ranks of the nobility of Asturias, León, and Galicia who lived in the 11th-century.
Bermudo Ovéquiz was the first-born son of Oveco Bermúdez and his wife Elvira Suárez. His paternal grandparents were Bermudo Vela—a descendant of Count Bermudo Núñez— and Elvira Pinióliz. His mother was granddaughter of rebel Rodrigo Romániz, nephew of Count Suero Gundemáriz, and she also descended from Osorio Gutiérrez, known as the "holy count". Bermudo lived in Asturias where he probably inherited properties from his grandmother Elvira Pinióliz. He is first recorded in medieval charters in 1045 and appears in 1053 confirming a donation by King Ferdinand I of León to the Monastery of San Pelayo in Oviedo. In 1075, he and his brother Vela Ovéquiz were engaged in a legal dispute with the bishop of Oviedo on account of the Monastery of Tol. This monastery had been donated previously to the Cathedral of Oviedo by Gontrodo Gundemáriz, daughter of Count Gundemaro Pinióliz. Other relatives were also involved in this dispute, including Count Fernando Díaz and his sister Jimena, the wife of Rodrigo Díaz de Vivar, El Cid. One of his sisters, Onecca, was the wife of Count Sancho Ordóñez. Even though he did not hold the title of count, he acted as the judge in a legal proceeding in 1087 involving the abbot of the Monastery of Lorenzana and the bishop of Mondoñedo.