The River Stour is a 60.5 mile long river in southern England. The source of the river is at Stourhead, in Wiltshire where it forms a series of artificial lakes which are part of the Stourhead estate, owned by the National Trust. The river flows south into Dorset, through Gillingham, the Blackmore Vale, Sturminster Newton, Blandford Forum and Wimborne Minster to its estuary at Christchurch, where it flows into the English Channel.

The river breaks through a ridge of high chalk downland between Sturminster Newton and Blandford Forum.

For many miles the river is followed by the now disused Somerset and Dorset Joint Railway, which bridged the river five times.

Because much of the river's course is across clay soil the river's waterlevel varies greatly. In summer low water level makes the river a diverse and important habitat, supporting many rare plants. In winter the river often floods, and is therefore bordered by wide and fertile flood plains.

A number of towns and villages in Dorset are named after the river, including East and West Stour, Stour Row, Stour Provist, Sturminster Newton, and Sturminster Marshall. Sturminster Newton is famous for its water mill and town bridge, which still bears the notice warning potential vandals that damaging the bridge is punishable by penal transportation.

See also

• Rivers of the United Kingdom