The Poraniidae (Asteroidea, Valvatacea) is recorded for the first time from Australian waters at deep-sea (>200 m) depths, including, at present, Australia’s deepest known asteroid occurrence from 3850 m. Three genera are reviewed, each represented by a single species,
Poraniomorpha tartarus n. sp.,
Marginaster paucispinus Fisher 1913, and
Marginaster patriciae McKnight 2006, which is reassigned to the new genus,
Bathymarginaster. Comparisons with other asteroid groups similar to the Poraniidae in Australian waters is made and a key to genera of the Poraniidae is provided.