Idmiston is a small village and civil parish in north‑eastern Wiltshire, England, lying close to the city of Salisbury and on the southern fringe of Salisbury Plain. The parish has a distinctly rural character of chalk downland, farmland and small woodlands and includes the adjacent settlement of Porton.
The area is best known for the long‑established science and defence complex at Porton Down and the nearby military airfield at Boscombe Down, both of which shape local employment alongside traditional farming and village services. Idmiston retains a compact community centred on its parish church and village amenities, while its proximity to the plain and nearby prehistoric features makes it popular with walkers and those interested in rural history.