Allocasuarina microstachya is a species of flowering plant in the family Casuarinaceae and is endemic to the south-west of Western Australia.

[2][3] This sheoak was first formally described in 1845 by Friedrich Anton Wilhelm Miquel who gave it the name Casuarina microstachya in Lehmann's Plantae Preissianae from specimens collected by Ludwig Preiss in 1839.

[4][5] It was reclassified in 1982 as Allocasuarina microstachya by Lawrie Johnson in the Journal of the Adelaide Botanic Gardens.

[7] Allocasuarina microstachya grows in heath in sand, laterite or gravel and is widely distributed in the southwest of Western Australia, from near Geraldton to Albany and the Munglinup River east of Ravensthorpe.

[3][2] Allocasuarina microstachya is listed as "not threatened" by the Western Australian Government Department of Biodiversity, Conservation and Attractions.