A total of eight coastal talitrid amphipods from Victoria, South Australia and Western Australia are documented. Three new genera (Australorchestia n.gen.; Bellorchestia n.gen. and Notorchestia n.gen.) and seven new species (Australorchestia occidentalis n.sp.; Bellorchestia richardsoni n.sp.; Notorchestia lobata n.sp.; N. naturaliste n.sp.; Platorchestia paraplatensis n.sp. Protorchestia ceduna n.sp. and Transorchestia marlo n.sp.) are described. Notorchestia australis (Fearn-Wannan, 1968) is reported from Twofold Bay, New South Wales, to the Eyre Peninsula, South Australia. Seven Australian and New Zealand "Talorchestia" species are transferred to Bellorchestia: B. chathamensis (Hurley, 1956); B. kirki (Hurley, 1956); B. marmorata (Haswell, 1880); B. pravidactyla (Haswell, 1880); B. quoyana (Milne Edwards, 1840); B. spadix (Hurley, 1956) and B. tumida (Thomson, 1885). Two Australian "Talorchestia" species are transferred to Notorchestia: N. australis (Fearn-Wannan, 1968) and N. novaehollandiae (Stebbing, 1899). Type material of Platorchestia platensis and Protorchestia lakei were re-examined for comparison with Australian species herein described. A key to the species herein described is provided.