Knettishall Heath is a 91.7-hectare (227-acre) biological Site of Special Scientific Interest west of Knettishall in Suffolk. A larger area of 176 hectares is the Knettishall Heath Nature Reserve, which is managed by the Suffolk Wildlife Trust. Despite its name, Knettishall Heath is in fact a diverse mosaic of habitats with woodland and riverside meadows, as well as large areas of heath.