Dionisio Hidalgo y Terán (Madrid, 1804 – Madrid, 1875) was a Spanish jurist, bibliographer, and editor. He studied law and held important positions such as librarian of the Royal Library and director of the National Library of Spain (1853-1867). He is mainly known for his monumental "General Dictionary of Spanish Bibliography," a key work for bibliographic study in Spain. He was a member of the Royal Academy of History and the Royal Spanish Academy, standing out for his contributions to law, history, and, above all, bibliography.