It has smooth reddish brown bark at first, later shedding in curling flakes, lance-shaped, sometimes curved adult leaves, club-shaped flower buds covered with a waxy, bluish white bloom, pink stamens with yellow anthers and urn-shaped fruit.Eucalyptus caesia is a mallee that typically grows to a height of 2 to 14 metres (6.6 to 45.9 ft) and forms a lignotuber.

Young branches are shiny red, covered with a waxy, bluish white bloom.

[4][5][6] Eucalyptus caesia was first formally described in 1867 by George Bentham from a collection made by James Drummond in 1847 and the description was published in Flora Australiensis.

[7][8] In 1982, Ian Brooker and Stephen Hopper described two subspecies, but the Australian Plant Census accepts these as synonyms: The specific epithet (caesia) is a Latin word meaning "bluish grey"[11] referring to the waxy cover of the small branches, flower buds and fruit.

[4] Caesia grows in crevices at the base of granite outcrops in scattered inland areas of the south-west, including in the Avon Wheatbelt and Mallee biogeographic regions.