Darwinia leiostyla is an erect shrub in the family Myrtaceae and is endemic to the south-west of Western Australia. It typically grows to a height of 0.3–1.5 m (1 ft 0 in – 4 ft 11 in) and has linear leaves up to about 10 mm (0.39 in) long crowded along the branches. Pendent, bell-shaped, flower-like inflorescences appear from May to January. These are clusters of small flowers surrounded by larger pink, red or white, petal-like bracts.
Darwinia leiostyla occurs in the Stirling Range and Middle Mount Barren on rocky sites, along streamlines and on slopes within gullies and ranges.
Darwinia leiostyla is classified as "Priority Four" by the Government of Western Australia Department of Parks and Wildlife, meaning that is rare or near threatened.
Darwinia leiostyla is listed in the following regions: