Sierra de Caballos or Sierra de los Caballos is a mountain range in the Maestrazgo and Bajo Aragón comarcas of Aragon, Teruel Province, Spain.

The Guadalopillo River flows along the northern side of the range.

It is located north of Castellote, at the eastern end of the Iberian System, roughly between Molinos and Berge.

The impressive Grutas de Cristal "glass caves" are located in the area of these mountains, within Molinos municipal term.

[2] There are other mountain ranges with the name "Sierra de Caballos" in the world.