The deep-water parapagurid hermit crab fauna from Australia is much more diverse then previously believed. The most recent information on parapagurids (De Saint Laurent, 1972) indicated the presence of three species and one subspecies in this region. The study of numerous unidentified or unreported parapagurid materials deposited in various Australian museums revealed the presence of at least 21 species. With the exception of three species of the genus Parapagurus Smith, 1879, all other parapagurids known from Australia are discussed. The heterogeneous genus Sympagurus Smith, 1883, is revised and restricted. Two new genera, Oncopagurus and Paragiopagurus, are proposed for a number of species previously assigned to Sympagurus. Four new species were discovered and are described, Sympagurus papposus, S. soela, S. villosus, and Oncopagurus cidaris. Of the previously recognised species, those found to be poorly described in the literature are diagnosed and illustrated. The Australian material is compared with types and/or supplemental material from other regions of the Pacific deposited in major museums or institutions. The affinities and important morphological variations of the species are discussed, and the overall distributions of the species updated. The subspecies of Sympagurus acutus (De Saint Laurent, 1972) are elevated to specific rank, and assigned to Paragiopagurus n.gen. The juvenile stages of S. brevipes (De Saint Laurent, 1972), an abundant species that reaches a large size, is described, and compared with the adults. Keys for the identification of all parapagurid genera and Australian species (except those of Parapagurus), are presented. The distribution of the species is summarised.