Wiltshire is a unitary authority area in the ceremonial county of Wiltshire, South West England. It was formed on 1 April 2009 following the abolition of Wiltshire County Council and the districts of Kennet, North Wiltshire, Salisbury, and West Wiltshire, all of which were replaced by Wiltshire Council, which is based at County Hall in Trowbridge. The remaining part of the ceremonial county is the Borough of Swindon, administered by a separate unitary authority. In 2024, the population was 523,700.
Salisbury, the district's only city, is its largest settlement, followed by Chippenham and Trowbridge.