The present section, Callianassida Dana, 1852, has recently been separated from the Thalassinida Dana, 1852; together these two sections constitute the infraorder Thalassinidea within the Decapoda. The section Thalassinida includes one superfamily, Thalassinoidea Dana, 1852, which is not considered herein. The Callianassida include two superfamilies, Axioidea Huxley, 1879 and Callianassoidea Dana, 1852. Those two superfamilies are reviewed according to the presence or absence of a rostral carina; cardiac sulcus(i); cardiac prominence; dorsal oval of the carapace; linea thalassinica; setal rows on carapace, abdomen, tail-fan, and pereiopods; the posterior whip of the maxilla 2 scaphognathite; a dorsal plate or lateral notch on the uropodal exopod; the male Plp1-2; and a median tooth of the prepyloric ossicle. In the present new classification, the section Callianassida thus comprises two superfamilies, Axioidea and Callianassoidea, 19 families including one new family and two families with a new status, 8 subfamilies including one subfam. nov., 116 genera including 41 gen. nov. and 8 genera sensu nov., and 419 species including 12 spp. nov. and 2 nom. nov.