It has two or three linear to lance-shaped leaves and up to seven cream-coloured to creamy-yellow flowers with light brown to reddish-brown markings.

There is a single smooth, yellow callus ridge 3–4 mm (0.12–0.16 in) long, along the mid-line of the labellum.

[2][3][4] Diuris suffusa was first formally described in 2016 by David Jones and Christopher J. French in Australian Orchid Review, from a specimen collected by French near the Trayning to Bencubbin road in 1999.

[4] Mottled donkey orchid grows in low shrubland and shrubby woodland in the area between Bencubbin, Trayning, Wyalkatchem and Koorda in the Avon Wheatbelt and Coolgardie bioregions of south-western Western Australia.

[2][3][4] Diuris suffusa is listed as "not threatened" by the Western Australian Government Department of Biodiversity, Conservation and Attractions.