The San Benito Formation is a Katian geologic formation of central Bolivia.

The 500 metres (1,600 ft) 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.

[1] The formation has provided the following fossils: