The Bluecheek butterflyfish, Chaetodon semilarvatus, is a butterflyfish of the family Chaetodontidae found in the Red Sea and Gulf of Aden, at depths of between 9.84 and 65.62 ft (3 and 20 m). Its length is up to 9.06 in (23 cm).
The Bluecheek butterflyfish is a common species found in areas where there is rich coral growth, often seen in pairs or small aggregations. It is occasionally observed hovering in a stationary position for extended periods under ledges of Acropora plate corals.
Reproduction is oviparous, and pairs are formed during breeding.