Hart Side (the hill side frequented by harts) is a subsidiary top on one of the east ridges of Stybarrow Dodd, which is a mountain (or fell) in the English Lake District, west of Ullswater on the main Helvellyn ridge in the Eastern Fells. With a height of 2,480 feet (756 m) Hart Side rises above the col separating it from Green Side by 75 feet (23 m).