The Ornate butterflyfish, Chaetodon ornatissimus, is a butterflyfish of the family Chaetodontidae found in the Indo-Pacific oceans from Sri Lanka to the Hawaiian, Marquesan and Ducie islands, north to southern Japan, south to Lord Howe and Rapa islands, and throughout Micronesia, at depths down to 118.11 ft (36 m). Its length is up to 7.87 in (20 cm).
The Ornate butterflyfish is white with orange to orange-brown oblique bands on the sides. Two broad yellow-edged black bars are on the head, one running across the eye and another on the snout.
It occurs in clear waters and coral-rich areas of lagoon and seaward reefs; however it is only common in seaward reefs. Juveniles are solitary, living among branching corals, while adults are almost always in pairs and are home-ranging. They feed exclusively on coral tissue.
Reproduction is oviparous, with pairs forming during breeding.