The Cathedral of Sigüenza, officially Catedral de Santa María de Sigüenza, is the seat of the bishop of Sigüenza, in the town of Sigüenza, in Castile-La Mancha, Spain. It was declared Bien de Interés Cultural in 1931. The works of the cathedral passed during the following centuries by different bishops, who were building in styles of each epoch until the central nave realized in full Gothic in the 15th century, in which the vaults of the crossing were covered, the future bishop Cardinal Mendoza. The ornamental part lasted until the 18th century.