North Walney is a National Nature Reserve on Walney Island, England. The reserve, which has an area of 646.5 ha, is notable as a habitat of Natterjack Toads. It is one of the sites in the Duddon Estuary which support one fifth of the national population of the rare amphibian.
The geology of the island is the product of erosion and reworking of glacial sediments. The reserve protects a sand dune system along with other habitats such as salt marsh and intertidal mudflats.
North Walney was formerly a separate Site of Special Scientific Interest, but it has been amalgamated with other SSSIs to form the Duddon Estuary Site of Special Scientific Interest. The Duddon Estuary has also been designated a Special Protection Area under the Birds Directive.
There is a separate nature reserve at South Walney, managed by the Cumbria Wildlife Trust, notable for its gulls.
Coordinates: 54°08′N 3°16′W / 54.14°N 3.26°W