Knowstone parish had a population of 226 in the 2011 census. The parish is fully enclosed within the Devon Character Area known as Witheridge and Rackenford Moor. The Devon County Council notes its features to include,
an elevated, open landscape with long views to Dartmoor and/or to Exmoor. Within the patchwork of pastoral fields are extensive areas of rough Culm grassland and heathland. These Culm ‘moors’ have a strong sense of remoteness, even wildness, which is accentuated by the relative lack of settlement and the wind-sculpted trees and hedgerows; they give an impression of how large areas of Devon might have looked before agricultural improvements such as drainage, ploughing and fertilizers. The presence in the landscape of numerous clusters of prehistoric barrows adds to this sense of history and changelessness. The strong textures of plantations, beech hedgerows, heathland and grasses contrast with the smooth improved agricultural land which surrounds them. Patches of colour in the landscape change with the seasons – golden, brown and green grasses, purple heather and bright yellow gorse.