The austromirine plant bug genus Irianocoris is revised, with three new Australian species described: I. carvalhoi n.sp., I. carbine n.sp., and I. schuhi n.sp. The previously described Australian species, I. australicus Carvalho, is redescribed, and its distributional range extended to Western Australia. The type species, I. italae Carvalho, from Indonesia (Irian Jaya) is redescribed and recorded from Papua New Guinea for the first time. A generic redescription and a key to species are given. The diagnostic characters of the male and female genitalia are illustrated.