Prostanthera densa, commonly known as villous mint-bush,[2] is a species of flowering plant in the family Lamiaceae and is endemic to near-coastal areas of New South Wales.

It is an erect, often compact shrub with aromatic branches, egg-shaped leaves, and mauve flowers with orange markings inside.

[2][3][4][5] Prostanthera densa was first formally described in 1920 by Arthur Andrew Hamilton in Proceedings of the Linnean Society of New South Wales.

[6][7] Villous mint-bush grows in forest and shrubland on the coast and nearby ranges between Nelson Bay and the Beecroft Peninsula.

The main threats to the species include land clearing for urban development, dieback caused by Phytophthora cinnamomi, dumping of garden refuse, weed invasion and disturbance by recreational users.