Indo-West Pacific: Aldabra Islands, Seychelles, Maldives, Andaman Sea, Thailand, Indonesia, Peninsular Malaysia, Sabah, Singapore, Viet Nam, Philippines, Ryukyu Islands, Ogasawara Islands, Palau, ?Kiribati, Papua New Guinea, Solomon Islands, Australia, Vanuatu, and New Caledonia. Replaced by Siganus trispilos in northwest Australia.

Head, body and fins orange-yellow; pale blue ocelli with darker blue margins on head, thorax and sides; spots about pinhead size, larger and more crowded on head, sometimes smaller on sides; ocelli may extend onto bases of dorsal and anal fins, and on bases of outer rays of caudal fin. Very small juveniles (up to 50 mm SL) may have vertical blue lines on side, fragmenting into the ocelli with increase in size. Orbit with a diffused-edged dark, triangular smudge; orange-brown iris Fin spines stout, pungent and venomous. Midline of thorax and ridges fully scaled.

Occurs in coral-rich areas of lagoons. Juveniles found in small schools in shallow seagrass beds and reefs; often found among Acropora corals. Adults usually in pairs on shallow coral reefs and feed on benthic algae. A food fish that is occasionally poisonous.