A new nematode species, Micropleura australiensis n. sp., is described on the basis of specimens found in the peritoneal cavity of the Australian freshwater crocodile, Crocodylus johnsoni Krefft, from the Ord River area, Western Australia. The new species is mainly characterized by the length of spicules (0.360–0.366 mm) and gubernaculum (0.096–0.105 mm), the number and arrangement of male caudal papillae (4 preanal and 6 postanal pairs), and the postequatorial vulva. To date, it is the first species of Micropleura reported from Australia. Micropleura trionyxi Agrawal, 1966, and M. lissemysia Chattervati, 1985, are considered junior synonyms of M. indica Khera, 1951.