It is an erect, spreading shrub with smooth bark, linear leaves and bright yellow flowers borne singly or in groups of up to four along a rachis up to 3 mm (0.12 in) long.

Persoonia dillwynioides is an erect, spreading shrub that typically grows to a height of 0.6–1.8 m (2 ft 0 in – 5 ft 11 in) with smooth, mottled grey bark and branchlets that are angular and densely hairy when young but become cylindrical and glabrous with age.

[2][3][4][5] Persoonia dillwynioides was first formally described in 1856 by Carl Meissner in de Candolle's Prodromus Systematis Naturalis Regni Vegetabilis.

[6][7] Fitzgerald persoonia occurs within 50 km (31 mi) of the coast of the south-west of Western Australia between the Gairdner River and Hopetoun where it grows in low heath.

[3][4] This geebung is classified as "not threatened" by the Western Australian Government Department of Parks and Wildlife.