A new monotypic genus in the orb-weaving spider family Araneidae Clerck, 1757 is described from Australia: Abbagen. nov., with Abba transversa (Rainbow, 1912) comb. nov. as the type species. It differs from all other genera in the family by somatic characters, specifically a patch of approximately five long spines on the prolateral surface of the first leg in males and an abdominal colouration with a pair of two central spots dorsally on a creamy-white surface. Specimens of A. transversacomb. nov. have been collected in Queensland and New South Wales, where the species is largely summer-mature. We also provide a genus level summary of all Australian Araneidae, currently consisting of 230 described species and eight subspecies in 46 genera.