The Diocese of Segorbe-Castellón (Latin, Segobiensis; Castellionensis, Valencian: Diòcesi de Sogorb-Castelló) is a Roman Catholic ecclesiastical territory located in north-eastern Spain, in the province of Castellón, part of the autonomous community of Valencia. The diocese forms part of the ecclesiastical province of Valencia, and is thus suffragan to the Archdiocese of Valencia. The seminary is in the Jesuit college given by king Carlos III. The convents of the Dominicans, Franciscans, the Augustinian nuns, and the Charterhouse (Cartuja) of Valdecristo have been converted to secular uses.