The plant bug genus Coridromius Signoret is revised. Twenty-one new species from Australia, the South Pacific, Asia and Africa are described (bicolor, boianotum, bulbopella, chenopoderis, confusus, crassus, drepanopenis, ephippius, epithema, falsicoleus, hermosus, lestoni, marmoreus, monotocopsis, pilbarensis, prolixipenis, pteraulos, ruwenzorii, sommelieri, tahitiensis, and thalame). Ten previously described species are redescribed (schuhi is excluded, as the type material is presumed lost and Linnavuori's original description and illustrations [Linnavuori, 1994] are not sufficient to distinguish schuhi from most other species). The genus Coridromoides Carvalho is synonymized with Coridromius, and its sole species, Coridromoides carinatus Carvalho, 1956, is transferred to Coridromius. A key to species, color habitus figures, illustrations of male genitalia, photographs of paragenital dissections, and scanning electron micrographs of structural details are provided. Detailed locality information and distribution maps of all species are included. Host plant data is provided for some species.