Buttermere Fells is a Site of Special Scientific Interest (SSSI) within Lake District National Park in Cumbria, England. The protected area includes many of the hills and mountains between the Buttermere lake valley near the village of Buttermere and the River Derwent valley near the village of Braithwaite. This protected area includes the mountains of Grasmoor, Crag Hill, Causey Pike and Hindscarth. The protected area includes much of the North Western Fells. This protected area contains exceptional examples of montane dwarf shrub heath communities.