Acacia hemsleyi is a species of flowering plant in the family Fabaceae and is endemic to tropical norhern Australia. It is a slightly resinous shrub or tree with linear to very narrowly elliptic, straight or slightly curved phyllodes, yellow flowers borne in spikes, and linear, firmly papery to thinly leathery pods.
Acacia hemsleyi is a slightly resinous shrub or tree that typically grows to a height of up to and has slightly fissured or shredding bark. Its phyllodes are linear to very narrowly elliptic, staight of slightly curved, long and wide with a bristly point, usually long at the tip. The phyllodes are thinly to moderately leathery and glabrous, with two or three slightly prominent veins and a gland up to above the pulvinus. The flowers are yellow and borne in spikes long. Flowering occurs from June to September and the pods are linear, firmly papery to thinly leathery, long and wide, slightly constricted between, and raised over the seeds. The seeds are more or less elliptic to oblong, long and dark brown.
Acacia hemsleyi was first formally described in 1917 by Joseph Maiden in the Journal and Proceedings of the Royal Society of New South Wales from specimens collected near the Fitzroy River, above the junction with the Hann River by William Vincent Fitzgerald in 1905. The specific epithet (hemsleyi) honours William Botting Hemsley.
This species of wattle occurs in tropical Australia north of 21ðS, in the Kimberley region of Western Australia, the north of the Northern Territory, and is very common in north-western Queensland. It grows along riverbanks and rocky creek beds and around permanent water sources.
Acacia hemsleyi is listed as "not threatened" by the Government of Western Australia Department of Biodiversity, Conservation and Attractions, as of "least concern" under the Northern Territory Government Territory Parks and Wildlife Conservation Act and the Queensland Government Nature Conservation Act 1992.