Chaetodon trichrous (Tahiti butterflyfish) is a species of fish in the family Chaetodontidae.

In 1984, André and Roland Bauchot Maugé proposed to include this species in a new genus Mesochaetodon.

[4] Chaetodon trichrous can reach a length of about 12 centimetres (4.7 in).

[2] The back half of the body is dark brown to black, while the front part is grayish, with a small vertical black stripe through the eye.

[2][1] This species is endemic to French Polynesia (Marquesas Islands, Society Islands, Tahiti, Tuamotu Archipelago) in the central-south Pacific Ocean.