Pterophyllum is a small genus of freshwater fish from the family Cichlidae known to most aquarists as angelfish. Angelfish are a species of cichlid fish found throughout the Amazon River system and in several South American countries (Amazon Basin, Orinoco Basin and various rivers in the Guiana Shield).

The three species of Pterophyllum are unusually shaped for cichlids being greatly laterally compressed, with round bodies and elongated triangular dorsal and anal fins. This body shape allows them to hide among roots and plants, often on a vertical surface. The unique appearance of the angelfish comes from its long fins that flow gracefully through the water as it swims, and varieties are typically identified based on different types of stripes or markings.