Sierra de Gúdar is a mountain range in the Gúdar-Javalambre and Maestrazgo comarcas of Aragon and the Alto Mijares comarca of the Valencian Community, Spain.

[1] This mountain range is located at the eastern end of the Iberian System and the Sierra de Nogueruelas is its easternmost prolongation.

Its summits are usually covered in snow in the winter and the 1710 m high Cabezo de las Cruces is one of the highest peaks of the Land of Valencia.

Mora de Rubielos is the most important town in this mountainous zone.

Valdelinares, also a village in the area, is the highest town in Spain among those which are head of a municipality.