Ostorhinchus is a genus of ray-finned fish in the family Apogonidae native to the Indian and Pacific Oceans.

Cardinalfishes are a family, Apogonidae, of ray-finned fishes found in the Atlantic, Indian, and Pacific Oceans; they are chiefly marine, but some species are found in brackish water and a few are found in fresh water. A handful of species are kept in the aquarium and are popular as small, peaceful, and colourful fish. The family includes about 370 species.