Trioceros is a genus of lizards in the family Chamaeleonidae, the chameleons, native to lowlands and highlands in the African mainland, ranging from Ethiopia south to Mozambique and west as far as Ghana.

Many species in the genus have various ornaments, such as one to four horns on the head, crests on the nape or throat, or spines or sail-like structures on the top of the back or tail.

They are primarily found in adult males, but generally reduced or even absent in females, and there are also many species in the genus where both sexes lack conspicuous ornaments.

It is likely that giving birth to live young is an adaption to temperature, as it in Trioceros generally is found in species from highlands.

The relatively cold highland climate slows the development of eggs laid in the ground; when instead retained inside the body until birth, a female can actively sun bask to increase the temperature.