Eucalyptus microcarpa, commonly known as grey box,[3] is a species of tree that is endemic to southeastern continental Australia.

It has rough, fibrous or flaky bark on the trunk, smooth whitish bark above, lance-shaped adult leaves, flower buds in groups of between seven and eleven, white flowers and oval, cylindrical or urn-shaped fruit.

Eucalyptus microcarpa is a spreading tree, sometimes with several trunks, that typically grows to a height of 25 m (82 ft) and forms a lignotuber.

[3][4][5][6][7] Grey box was first formally described in 1902 by Joseph Maiden who gave it the name Eucalyptus hemiphloia var.

[3][6][14] This eucalypt is a component of the grey box (E. microcarpa) grassy woodlands and derived native grasslands of south- eastern Australia that is listed as "endangered" under the Australian Government Environment Protection and Biodiversity Conservation Act 1999.