Stourhead is a 1,072-hectare estate at the source of the River Stour in the southwest of the English county of Wiltshire, extending into Somerset. The estate is about 4 km northwest of the town of Mere and includes a Grade I listed 18th-century Palladian mansion, the village of Stourton, gardens, farmland, and woodland. Stourhead has been part-owned by the National Trust since 1946.