Sierra de San Just (Aragonese: Sierra de Sant Chust) is a mountain range in the Cuencas Mineras comarca of Aragon, Teruel Province, Spain. The highest point in the range is San Just (1,522 m). This range is located in one of the coldest and most rugged regions of Aragon.

Landslides are relatively frequent in the San Just mountains.

Besides the mountain ranges, the Plains of Visiedo (Spanish: Llanos de Visiedo) near Visiedo, the Altos del Zancado, and the area surrounding Ejulve, are all part of the Sierra de San Just geographic zone.

Road N-211 crosses the range at Gargallo and skirts the mountainsides of the chain.

There are lignite deposits in the Sierra de San Just range. The Utrillas mines were exploited since ancient Roman times.

• List of mountains in Aragon
• Cuencas Mineras

• Geografia de la Provincia de Teruel
• Region of Cuencas Mineras
• Paragliding - Sierra de San Just
• Utrillas - Historia
• Gargallo, en la Sierra de Sant Just
• Cuencas Mineras - Tourism (in Spanish)