Barun Valley (बरुण उपत्यका) is a Himalayan valley situated at the base of Mt. Makalu in the Sankhuwasabha district of Nepal. This valley lies entirely inside the Makalu Barun National Park.

The Barun Valley provides stunning contrasts, where high waterfalls cascade into deep gorges, craggy rocks rise from lush green forests, and colorful flowers bloom beneath white snow peaks. This unique landscape shelters some of the last pristine mountain ecosystems on Earth. Rare species of animals and plants flourish in diverse climates and habitats, relatively undisturbed by humankind.

The valley was created by the Barun River which becomes a glacier in winter. The river is known as Chukchuwa in the local indigenous Limbu language. The study has shown that this place was originally inhabited by Yakkha and Limbu centuries ago.