Sierra de los Agustinos is a mountain range in Guanajuato state of central Mexico.

The volcanic rocks which make up the Sierra are porous and highly fractured, and the Agustinos Aquifer is important source of groundwater in the adjacent lowlands.

Characteristic trees include palo dulce (Eysenhardtia polystachya) tepeguaje (Lysiloma sp), oak (Quercus spp.

Native mammals include the bobcat (Lynx rufus), ringtail (Bassariscus astutus), white-nosed coati (Nasua narica), raccoon (Procyon lotor), Mexican long-nosed bat (Leptonycteris nivalis), and Saussure's shrew (Sorex saussurei).

Native birds include Swainson's hawk (Buteo swainsoni), Mexican falcon (Falco mexicanus), brown-backed solitaire (Myadestes occidentalis).