A glaciated valley is one formed by the process of glaciation. They have a characteristic U-shape, with steep, straight sides, and a flat bottom. Glaciated valleys are formed when a glacier travels across and down a slope, carving the valley by the action of scouring. When the ice recedes or thaws, the valley remains, often littered with small boulders that were transported within the ice.

Glaciated valleys are a common feature of the landscape of Wales and Scotland, as well as upland parts of England such as the Lake District. They are also found throughout Scandinavia, Europe, Canada and parts of North America.

A hanging valley is a type of glacial valley.