Boosmansbos Wilderness Area, Nature reserve in Langeberg Mountains, South Africa.

Boosmansbos Wilderness Area is a protected nature reserve in the Langeberg Mountains, covering mountainous terrain with indigenous forests and deep gorges throughout. The landscape includes the Grootberg peak and numerous trails that wind through dense vegetation and rocky outcrops.

Boosmansbos means "angry man's forest", named after a hermit who lived in the area in the early 19th century and was known to scare youngsters who came to his apiaries. The wilderness area was later proclaimed to protect the mountain fynbos and valley forest, and in the southwest it encloses the Grootvadersbosch Nature Reserve, the most western natural forest in South Africa. Together with that reserve it forms part of the Cape Floral Region recognised by the United Nations as a World Heritage Site.

The name Boosmansbos means "angry man's forest", after an early 19th-century hermit who lived here and scared youngsters away from his apiaries. Together with the adjoining Grootvadersbosch Nature Reserve it forms one of eight protected areas of the Cape Floral Region recognised by the United Nations as a World Heritage Site.

The wilderness area is reached from Heidelberg, about 20 km to the south. Its 64 km of footpaths include a 27 km circular route that can be completed in two days. Rain can fall in any month, and hot bergwind conditions occur in mid-summer and mid-winter.

Boosmansbos is one of eight protected areas of the Cape Floral Region recognised by the United Nations as World Heritage. Its fynbos holds rare heathers such as Erica blenna, E. langebergensis and E. barrydalensis, and about 184 bird species are seen regularly, among them the red-chested flufftail, martial eagle and Natal spurfowl.