Donax carinatus is a species of small saltwater clam, a marine bivalve mollusc species in the family Donacidae.
Shells of Donax carinatus can reach a length of , a height of and a diameter of . These shells are triangular-shaped, elongated, with a strong sculpture and anteriorly rostrated. The basic color of the external surface is purple and yellowish brown, with a purple interior.
This species is present from Mexico to Colombia, in depths to 24 m.