The Australasian spiny trapdoor spiders of the family Idiopidae (subfamily Arbanitinae) are revised at the generic level, using a multi-locus molecular phylogenetic foundation and comprehensive sampling of all known lineages. We propose a new family- and genus-group classification for the monophyletic Australasian fauna, and recognise 10 genera in four tribes. The Arbanitini Simon includes Arbanitis L. Koch, 1874 (61 species), Blakistonia Hogg, 1902 (one species) and Cantuaria Hogg, 1902 (43 species). The Aganippini Simon includes Bungulla Rix, Main, Raven & Harvey, gen. nov. (two species), Eucanippe Rix, Main, Raven & Harvey, gen. nov. (one species), Eucyrtops Pocock, 1897 (two species), Gaius Rainbow, 1914 (one species) and Idiosoma Ausserer, 1871 (14 species). The Cataxiini Rainbow and Euoplini Rainbow include just Cataxia Rainbow, 1914 (11 species) and Euoplos Rainbow, 1914 (12 species), respectively. Two distinctive new genera of Aganippini are described from Western Australia, and several previously valid genera are recognised as junior synonyms of existing genus-group names, including Misgolas Karsch, 1878 (= Arbanitis; new synonymy), Aganippe O. P.-Cambridge, 1877 (= Idiosoma; new synonymy) and Anidiops Pocock, 1897 (= Idiosoma; new synonymy). Gaius stat. rev. is further removed from synonymy of Anidiops. Other previously hypothesised generic synonyms are supported by both morphology and molecular phylogenetic data from 12 genes, including the synonymy of Neohomogona Main, 1985 and Homogona Rainbow, 1914 with Cataxia, and the synonymy of Albaniana Rainbow & Pulleine, 1918, Armadalia Rainbow & Pulleine, 1918, Bancroftiana Rainbow & Pulleine, 1918 and Tambouriniana Rainbow & Pulleine, 1918 with Euoplos. At the species level, the identifications of Eucy. latior (O. P.-Cambridge, 1877) and I. manstridgei (Pocock, 1897) are clarified, and three new species are described: Bungulla bertmaini Rix, Main, Raven & Harvey, sp. nov., Eucanippe bifida Rix, Main, Raven & Harvey, sp. nov. and Idiosoma galeosomoides Rix, Main, Raven & Harvey, sp. nov., the latter remarkable for its phragmotic abdominal morphology. The Tasmanian species Mygale annulipes C. L. Koch, 1842 is here transferred to the genus Stanwellia Rainbow & Pulleine, 1918 (family Nemesiidae), comb. nov., Arbanitis mestoni Hickman, 1928 is transferred to Cantuaria, comb. nov. and Idiosoma hirsutum Main, 1952 is synonymised with I. sigillatum (O. P.-Cambridge, 1870), new synonymy. In addition to the morphological synopses and an illustrated key to genera, molecular diagnoses are presented for all nominal taxa, along with live habitus and burrow images to assist in field identification. The Australasian idiopid fauna is highly diverse, with numerous new species known from all genera. As a result, this study provides a taxonomic and nomenclatural foundation for future species-level analyses, and a single reference point for the monographic documentation of a remarkable fauna.