The Australian Nephtyidae are represented by 13 species in four genera, Aglaophamus (4 species), Inermonephtys (1 sp.), Micronephthys (1 sp.) and Nephtys (7 spp.). Five new species are described, Aglaophamus gippslandicus n.sp., A. profundus n.sp., Nephtys inornata n.sp., N. mesobranchia n.sp., and N. semiverrucosa n.sp. Nephtys vikingensis Paxton, 1974 is synonymised with N. longipes Stimpson, 1856 and Micronephthys sphaerocirrata (Wesenberg-Lund, 1949) is recorded from Australia for the first time. Descriptions are provided for all species examined.