Theropithecus brumpti was a large terrestrial monkey that lived in the mid to late Pliocene.

This fossil primate is mostly known from skulls and mandibles found in Pliocene deposits excavated in the Shungura Formation, at the Omo River, Ethiopia.

Males grew very large, as evidenced by a specimen found at Lomekwi, Kenya, which was estimated to have weighed approximately 43.8 kilograms.

[1] This species was largely terrestrial, with the size of adult males making any significant arboreal lifestyle unlikely.

From the locations of T. brumpti finds, the species lived in riverine forest habitats.