Cafius chilensis sp. nov. is described from the Chilean coast. Adults of the new species were collected under seaweed and are similar to those of C. algophilus Broun, 1894 and C. maritimus (Broun, 1880) from the New Zealand coast. Morphological comparison for these three species is presented. A description, SEM and habitus photographs, and illustrations of diagnostic characters of the new species are provided to facilitate identification.