Elvira of Castile was a noblewoman from the Kingdom of Castile in the 11th century. She was the daughter of Sancho II of Castile and Muniadona of Castile. Elvira played a significant role in the political landscape of her time, particularly through her marriage alliances, which were common among nobility to strengthen ties between families. Elvira married Ramiro I of Aragon, which helped to solidify relations between Castile and Aragon. Her descendants continued to influence the region, contributing to the development of the Spanish monarchy. Elvira's life reflects the importance of women in medieval politics, often acting as key figures in dynastic strategies.