Gesomyrmex is a genus of ants in the subfamily Formicinae. The genus contains six extant species, known from the Indomalayan region, and nine fossil species. Of the extant species, four are known only from workers (G. chaperi, G. howardi, G. kalshoveni and G. spatulatus) and two only from females (G. luzonensis and G. tobiasi). The extinct species "G. expectans" and "G. miegi", formerly placed in the genus, were excluded by Dlussky et al., 2009. The living species are arboreal typically building nests in the twigs of trees.