Brachycephalus brunneus is a species of frog in the Brachycephalidae family endemic to Brazil, known only from Pico Caratuva, Campina Grande do Sul, Paraná. It is found in thick leaf-litter in Atlantic forest and is diurnal, active especially from December to February. Its natural habitat is subtropical or tropical moist montane forests.It is threatened by habitat loss for cattle pasture and agriculture such as sugar cane, coffee, and exotic trees.