The Dotted Butterflyfish (Chaetodon semeion) is a species of butterflyfish (family Chaetodontidae). It is found in the Indian Ocean and Pacific Ocean from the Maldives to the Tuamotu Islands, north to the Ryukyu Islands and south to the Great Barrier Reef. It grows to a maximum of 26 cm (10 in) long. The body is golden yellow. The base of the posterior portions of the dorsal and anal fins is black, a prominent vertical black bar runs across the eye and there are diagonal rows of black dots on the sides. A filament originating from the soft portions of the dorsal fin rays trails posteriorly.