The civil parish has an area of 14.5 km² and in the 2001 census had a population of 4,502 in 2,110 households. For the purposes of local government, the parish falls within the district of King's Lynn and West Norfolk.
Sandringham House, a favoured holiday home of Queen Elizabeth and several of her predecessors, lies just to the south of Dersingham in the parish of Sandringham. The nearby Dersingham Bog National Nature Reserve, managed by English Nature, contains habitats ranging from marshland to heathland and woodland. Birds such as the redpoll, crossbill, long-eared owl, tree pipit, sparrowhawk and nightjar can be found here.