Body laterally flattened with an oval profile, blue to greenish blue in color with yellow rims on their scales. Ventral and pectoral fins and tail entirely yellow.
Terminal phase with a dark blue spot on the forehead, speckled and ringed with brilliant blue, forming the 'crown'. Lips purplish blue (H. ciliaris).
Size up to 45 cm.
Juveniles dark blue with three brilliant blue to white bars, the second bar clearly curved. A dark blue bar with brilliant blue borders across the eye. Lips yellow, and a yellow area from around the pectoral to the ventral fins. Tail yellow.
Found in coral reefs, where they occur solitarily or in pairs, down to 70 m. Juveniles pick off parasites from the bodies of other fish, while adults mainly feed on sponges.
Common to occasional Florida, Bahamas and Caribbean.
Terminal phases of the related Blue angelfish (Holacanthus bermudensis) are purplish to blue-green, often with a gray cast. Only the borders of the tail and pectoral fins are yellow. Juveniles also with three bars, but the second bar is straight.
Queen and Blue angelfish occasionally interbreed, resulting in fish that share some distinctive markings from both species. These hybrids were once incorrectly described as a separate species: Townsend angelfish (Holacanthus townsendi).