Ischnochiton cariosus, commonly known as the corroded ischnochiton, is a species of chiton in the Ischnochiton genus that lives under rocks in the intertidal and shallow subtidal waters of southern Australia and up the coast of Western Australia as far as Shark Bay. It is commonly found throughout its range and is often found with Ischnochiton torri. It grows to 35 mm long and has a pale-straw colour.