Pimelea williamsonii, commonly known as Williamson's rice-flower,[2] is a species of flowering plant in the family Thymelaeaceae and is endemic to the southern continental Australia.

It is a bushy annual subshrub with more or less elliptic leaves and elongated heads of many hairy, brownish flowers.

Pimelea williamsonii is a bushy annual subshrub that typically grows to a height of 10–30 cm (3.9–11.8 in) and has densely hairy young stems.

[2][3][4] Pimelea williamsonii was first formally described in 1919 by John McConnell Black in the Transactions and Proceedings of the Royal Society of South Australia.

[5][6] The specific epithet (williamsonii) honours Herbert Bennett Williamson who discovered the species near Pinnaroo in 1917.