The council was established in 1889 as the principal local authority for the historic county of Wiltshire, at the same time as a large number of other county councils covering most of England and Wales.
[1] On 31 January 1889 the first meeting took place, and several aldermen were chosen to join the elected members.
Although it gained further powers over the next hundred years, in form and area the county council continued little changed until April 1997, when the Borough of Swindon became a unitary authority in its own right, taking almost a third of the population out of the area of Wiltshire County Council.
At the time of the 2009 structural changes to local government in England, Wiltshire County Council and the four districts then within its geographical area were replaced by the new Wiltshire Council, a unitary authority covering the same area, with elections to that continuing to be held every four years.
Between April and June 2009, the existing county councillors were the members of the new authority.