Ricinocarpos rosmarinifolius is a species of flowering plant in the family Euphorbiaceae and is endemic to the Kimberley of northern Western Australia.

Ricinocarpos rosmarinifolius is an erect, slender, monoecious shrub that typically grows to height of up to 2 m (6 ft 7 in), its young branchlets covered with white, star-shaped hairs.

Each flower has 5 sepals joined at the base and 5 white petals.

Flowering has been observed in February, May, June and September, and the fruit is an elliptic capsule 7.5–9.0 mm (0.30–0.35 in) long.

[2][3] Ricinocarpos rosmarinifolius was first formally described in 1873 by George Bentham in Flora Australiensis from specimens collected by Allan Cunningham.