Homalaspis is a genus of crabs in the family Platyxanthidae. It is monotypic, the sole species being Homalaspis plana, also known as the purple stone crab or Chilean stone crab.

Homalaspis plana occurs in the East Pacific from the Galápagos Archipelago to southern Patagonia. There is a single record from the west coast of South Africa, likely resulting from shipping or aquaculture imports.

Homalaspis plana lives in the intertidal zone and down to . It is a commercially valuable species.