The San Benito Formation is a Katian geologic formation of central Bolivia. The formation belongs to the Cochabamba Group, overlies the Anzaldo Formation and is overlain by the Cancañiri Formation. The thick formation comprises a succession of shallow water quartzitic sandstones with minor interbeds of dark grey micaceous siltstones. Shelly fossils have been found at few horizons and consist mainly of linguliformean brachiopods, bivalves, and a few homalonotid trilobite remains. Poorly preserved graptolites occur occasionally in the shaly beds.
The formation has provided the following fossils: