Baldersdale Woodlands is a Site of Special Scientific Interest in the Teesdale district of south-west County Durham, England. It consists primarily of ancient, semi-natural woodland growing on steep valley slopes, including scree, on both banks of the River Balder over a stretch of some 3 km, upstream (i.e. west) of the village of Cotherstone. The site has a rich faunal assemblage and the woodland and associated stretch of the river is home to a variety of birds, including dipper and goosander.