Allocasuarina simulans, commonly known as Nabiac casuarina,[2] is a species of flowering plant in the family Casuarinaceae and is endemic to a restricted part of eastern New South Wales.

[4][5] Allocasuarina simulans was first formally described in 1989 by Lawrie Johnson in Flora of Australia from specimens collected at an old airstrip near Nabiac in 1975.

[8] This she-oak is only known from near Myall Lakes, where it grows in sandy heath, shrubland and open woodland between Booti Booti National Park and Nabiac in eastern New South Wales.

[3][5][6] Nabiac casuarina is listed as "vulnerable" under the Australian Government Environment Protection and Biodiversity Conservation Act 1999 and the New South Wales Government Biodiversity Conservation Act 2016.

The main threats to the species include disturbance from sand mining, inappropriate fire regimes and weed invasion, especially by exotic species such as Lantana camara.