The Forest Sandstone is a geological formation in southern Africa, dating to roughly between 200 and 190 million years ago and covering the Hettangian to Sinemurian stages of the Jurassic Period in the Mesozoic Era.

Fossils of the prosauropod dinosaur Massospondylus and the primitive sauropod Vulcanodon have been recovered from the Forest Sandstone.

The formation is a sedimentary unit, consisting mainly of aeolian sands and silts with interbedded fluvial sediments,[2] laid down during a period of increasing aridity.

[9] The Forest Sandstone has been correlated to the Clarens Formation of the Great Karoo Basin in South Africa.

[5][7][8] The Forest Sandstone is the major groundwater-bearing unit of the Upper Karoo Group.