Stockbridge Common Marsh is a 64.8-hectare (160-acre) biological Site of Special Scientific Interest south of Stockbridge in Hampshire.

[1][2] It is owned by the National Trust.

[3] This site stretches for 2 kilometres (1.2 miles) along the flood plain of the River Test.

It has wetland habitats including marsh, fen, carr, alluvial meadows and a large shallow lake.

The marsh has a rich variety of flora, with 180 species of flowering plants, including bog pimpernel, adder’s-tongue fern, marsh valerian and bogbean.