Boronia gunnii is an erect shrub that grows to about 1.2 m (4 ft) high and has branches with minute, bristle like hairs between the leaf bases and small, blunt glands.

[2][3][4] Boronia gunnii was first formally described in 1855 by Joseph Dalton Hooker who published the description in The botany of the Antarctic voyage of H.M.

Discovery ships Erebus and Terror from a specimen collected by Ronald Campbell Gunn "on rocks on the South Esk River, near Launceston".

[2] Gunn's boronia grows in the flood zones of watercourses, in rock crevices or between boulders.

[2][4][7] Boronia gunnii is listed as "vulnerable" under the Commonwealth Government Environment Protection and Biodiversity Conservation Act 1999 (EPBC) Act and under the Tasmanian Government Threatened Species Protection Act 1995.The main threats to the species are dieback caused by Phytophthora cinnamomi, inappropriate fire regimes, changes in water flow and weed invasion.