A new genus and species from Brazil, oraea brasiliensis, is described and illustrated, and its phylogenetic affinities are discussed. The genus oraea is diagnosed by the V-shaped buccular juncture, the presence of jugal ridge, evaporative area extensive, mesepimeron barely emergent, male protibia and mesofemur spinose, posterior pronotal lobe with four rounded yellowish macula, unspined aedeagus with two vesical lobes and the gonoporal process enlarged distally. The male of Orthaea meloae Dellapé & Montemayor is described, and the male genitalia of O. meloae and O. alveusincola Harrington are also described and illustrated; O. consuta Dallas is recorded for the first time from Belize, O. meloae from Panama, and O. montana Dellapé & Montemayor from Bolivia. A cladistic analysis of the species of Orthaea Dallas is performed. One most parsimonious tree was obtained, with the following topology: (Myodocha serripes ((Heraeus triguttatus, Paisana brachialis) (oraea brasiliensis (O. consuta ((O. procincta, O. montana) (O. alveusincola, O. meloae)))))). Orthaea was recovered as monophyletic supported by seven synapomorphies.