Muiriantha hassellii is a small under shrub to 0.15–30 cm (0.059–11.811 in) high with branchlets sparsely covered in soft, thin, separated, star-shaped hairs.

The leaves are arranged alternately, aromatic, upright, narrowly elliptic, 10–15 mm (0.39–0.59 in) long, leathery, smooth and sparsely covered in soft hairs.

The fragrant inflorescence are terminal on branches, tubular 2–2.5 cm (0.79–0.98 in) long, pendulous with small to medium sized bracts.

[6][7] The specific epithet (hassellii) was named in honour of Albert Hassell who collected the plant from the west end of the Stirling Range.

[6] This species has a restricted distribution found only in the south-west of Western Australia at Mount Manypeaks and the Stirling Range on heath in peaty sand, rocky clay on hillsides.