Duke of Nájera (Spanish: Duque de Nájera) is a hereditary title in the peerage of Spain, which was bestowed by the Catholic Monarchs of Spain on 30 August 1482 to Don Pedro Manrique de Lara, II Count of Treviño and Ricohombre de Castilla, as a reward for his services to the Crown. In 1520, King Charles I supplemented the title of duke with that of Grandee of Spain.
The title refers to the town of Nájera in the La Rioja region.
The Dukes of Nájera ruled Nájera until the year 1600, when the last Duke in the male line died without a son. The title passed to his daughter Luisa.