Sierra de San Just (Aragonese: Sierra de Sant Chust) is a mountain range in the Cuencas Mineras comarca of Aragon, Teruel Province, Spain.

This range is located in one of the coldest and most rugged regions of Aragon.

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

[citation needed] There are lignite deposits in the Sierra de San Just range.

The Utrillas mines were exploited since ancient Roman times.