Westbury was a parliamentary constituency in Wiltshire from 1449 to 2010. It was represented in the House of Commons of England until 1707, and then in the House of Commons of Great Britain from 1707 to 1800, and finally in the House of Commons of the Parliament of the United Kingdom from 1801 until 2010.
Until 1885, it was a parliamentary borough, returning two Members of Parliament (MPs) until 1832 and only one from 1832 to 1885. The parliamentary borough was abolished in 1885, when the name was transferred to a county constituency returning one MP. Elections used the bloc vote system when two MPs were returned, and the first-past-the-post system of election when one seat was contested.
Westbury returned a Conservative Member at every election after 1924.
Boundaries
thumb|The Westbury borough constituency before 1832, outlined in black, and after the Reform Act, outlined in red, when it included the whole town and the villages within the ancient parish
Originally a small pocket borough, covering only a small part of the parish of Westbury, the Reform Act 1832 expanded it to take in the whole parish, which then included Bratton, Heywood, Dilton Marsh, Dilton, and most of today's Chapmanslade. In 1885, the Westbury parliamentary borough was abolished, and a new county constituency of Westbury was created, with the same name, but covering a much larger area. The boundaries of that changed over the years, until in 2010 the Westbury constituency was abolished and replaced by South-West Wiltshire.
1885–1918: The Sessional Divisions of Bradford-on-Avon, Melksham, Trowbridge, Westbury, and Whorwellsdown, and part of the Sessional Division of Warminster.
1918–1950: The Urban Districts of Bradford-on-Avon, Melksham, Trowbridge, Warminster, and Westbury, and the Rural Districts of Bradford-on-Avon, Melksham, Mere, Warminster, and Westbury with Whorwellsdown.
1950–1974: The Urban Districts of Bradford-on-Avon, Melksham, Trowbridge, Warminster, and Westbury, and the Rural Districts of Bradford-on-Avon and Melksham, Mere and Tisbury, and Warminster and Westbury.
1974–1983: As before but with redrawn boundaries as a result of the Local Government Act 1972.
1983–1997: The District of West Wiltshire, and the District of Salisbury wards of Knoyle, Mere, and Western.
1997–2010: The District of West Wiltshire wards of Adcroft, Bradford-on-Avon North, Bradford-on-Avon South, College, Corsley, Dilton Marsh, Drynham, Ethandune, Holt, John O'Gaunt, Manor Vale, Mid Wylye Valley, Park, Paxcroft, Shearwater, Summerham, Warminster East, Warminster West, Weavers, Westbrook, Westbury with Storridge, and Wylye Valley, and the District of Salisbury wards of Knoyle, Mere, and Western.
Following a review of parliamentary representation in Wiltshire, the Boundary Commission for England created two new constituencies in the county. Chippenham, mostly from the adjoining North Wiltshire, plus the town of Bradford-on-Avon at the northern end of the Westbury constituency, while the rest of Westbury saw minor changes to its composition and was renamed South West Wiltshire. These changes were approved in 2005, to take effect at the following general election, which took place in 2010.
Members of Parliament
Westbury borough (before 1885)
MPs 1449–1640
{| class="wikitable"
|-
!Parliament!!First member!!Second member
|-
| 1491|| Sir Thomas Long of Draycot
|-
| 1510-1523|| No names known
|-
| 1529|| Thomas Kirton|| Thomas Temys
|-
| 1562–3|| Hugh Ryley|| John Dyster
|-
| 1601|| Henry Jackman!!First party!!!!Second member
| <!-- party -->
|-
| 1678
| style="color:inherit;background-color: white" |
| Henry Bertie
| <!-- party -->
|-
|February 1679
| style="color:inherit;background-color: white" |
| William Trenchard
| <!-- party -->
|-
|August 1679
| style="color:inherit;background-color: white" |
| Henry Bertie
| <!-- party -->
|-
| 1680
| style="color:inherit;background-color: white" |
| Edward Norton
| <!-- party -->
|rowspan="2" style="color:inherit;background-color: white" |
|rowspan="2"| William Trenchard
|rowspan="2"| <!-- party -->
|-
| 1681
| style="color:inherit;background-color: white" |
| John Ashe
| <!-- party -->
|-
| 1685
|rowspan="3" style="color:inherit;background-color: white" |
|rowspan="3"| Richard Lewis
|rowspan="3"| <!-- party -->
| style="color:inherit;background-color: white" |
| James Herbert
| <!-- party -->
|-
| 1689
| style="color:inherit;background-color: white" |
| Peregrine Bertie
| <!-- party -->
|-
| 1695
|rowspan="2" style="color:inherit;background-color: white" |
|rowspan="2"| Robert Bertie
|rowspan="2"| <!-- party -->
|-
| 1701
| style="color:inherit;background-color: white" |
| Henry Bertie
| <!-- party -->
|-
|July 1702
| style="color:inherit;background-color: white" |
| William Trenchard
| <!-- party -->
| style="color:inherit;background-color: white" |
| Thomas Phipps
| <!-- party -->
|-
|December 1702
| style="color:inherit;background-color: white" |
| Willoughby Bertie
| <!-- party -->
|-
|June 1715
| <!-- party -->
|rowspan="3" style="color:inherit;background-color: white" |
|rowspan="3"| Francis Annesley
|rowspan="3"| <!-- party -->
|-
| March 1723 by-election
| style="color:inherit;background-color: white" |
| John Bance
| <!-- party -->
| style="color:inherit;background-color: white" |
| Paul Methuen
| <!-- party -->
|-
| 1748
|rowspan="3" style="color:inherit;background-color: white" |
|rowspan="3"| Peregrine Bertie
|rowspan="3"| <!-- party -->
|-
|1768
| style="color:inherit;background-color: white" |
| William Blackstone
| <!-- party -->
|-
| 1770 by-election
| style="color:inherit;background-color: white" |
| Hon. Charles Dillon
| <!-- party -->
|-
|1774
|rowspan="2" style="color:inherit;background-color: white" |
|rowspan="2"| Hon. Thomas Wenman
|rowspan="2"| <!-- party -->
| style="color:inherit;background-color: white" |
| Nathaniel Bayly
| <!-- party -->
|-
| 1779 by-election
|rowspan="6" style="color:inherit;background-color: white" |
|rowspan="6"| Samuel Estwick I
|rowspan="6"| <!-- party -->
|-
|1780
| style="color:inherit;background-color: white" |
| (Sir) John Whalley-Gardiner
| <!-- party -->
|-
|1784
| style="color:inherit;background-color: white" |
| Chaloner Arcedeckne
| <!-- party -->
|-
| 1786 by-election
| style="color:inherit;background-color: white" |
| John Madocks
| <!-- party -->
|-
|1790
| style="color:inherit;background-color: white" |
| Ewan Law
| <!-- party -->
|-
|January 1795 by-election
|rowspan="2" style="color:inherit;background-color: white" |
|rowspan="2"| Samuel Estwick II
|rowspan="2"| <!-- party -->
|-
|November 1795 by-election
| style="color:inherit;background-color: white" |
| Edward Wilbraham-Bootle
| <!-- party -->
|-
|May 1796
|rowspan="3" style="color:inherit;background-color: white" |
|rowspan="3"| Sir Henry St John-Mildmay, Bt
|rowspan="3"| <!-- party -->
| style="color:inherit;background-color: white" |
| George Ellis
| <!-- party -->
|-
|October 1796 by-election
| style="color:inherit;background-color: white" |
| George Harcourt
| <!-- party -->
|-
| 1800 by-election
| style="color:inherit;background-color: white" |
| John Simon Harcourt
| <!-- party -->
|-
|1802
| style="color:inherit;background-color: white" |
| William Baldwin
| <!-- party -->
| style="color:inherit;background-color: white" |
| Charles Smith
| <!-- party -->
|-
|1806
| style="color:inherit;background-color: white" |
| William Jacob
| <!-- party -->
| style="color:inherit;background-color: white" |
| John Woolmore
| <!-- party -->
|-
|May 1807
| style="color:inherit;background-color: " |
| Edward Lascelles
| Tory
|rowspan="2" style="color:inherit;background-color: white" |
|rowspan="2"| Benjamin Shaw
| <!-- party -->
|-
| 1814 by-election
|rowspan="2" style="color:inherit;background-color: " |
|rowspan="2"| Ralph Franco
|rowspan="2"| Tory
|-
|1818
|rowspan="2" style="color:inherit;background-color: white" |
|rowspan="2"| Lord Francis Conyngham
|rowspan="2"| <!-- party -->
|-
| 1819 by-election
| style="color:inherit;background-color: " |
| William Leader Maberly
| Whig
|-
| style="color:inherit;background-color: " |
| 1837
| John Ivatt Briscoe
| Whig
|-
| style="color:inherit;background-color: " |
| 1841
| Sir Ralph Lopes
| Conservative
|-
| style="color:inherit;background-color: " |
| 1857
| Sir Massey Lopes
| Conservative
|-
| style="color:inherit;background-color: " |
| 1868
| John Lewis Phipps
| Conservative
|-
| style="color:inherit;background-color: " |
| 1869 by-election
| Charles Paul Phipps
| Conservative
|-
| style="color:inherit;background-color: " |
| 1874
| Abraham Laverton
| Liberal
|-
| style="color:inherit;background-color: " |
| 1880
| Charles N. P. Phipps
| Conservative
|-
|
| 1885
|colspan="2"| Borough abolished - name transferred to a new county division
|}
Westbury County constituency (1885–2010)
{| class="wikitable"
|-
!colspan="2" | Election !! Member
| Conservative
|-
| style="color:inherit;background-color: " |
| 1964
| Sir Dennis Walters
| Conservative
|-
| style="color:inherit;background-color: " |
| 1992
| David Faber
| Conservative
|-
| style="color:inherit;background-color: " |
| 2001
| Andrew Murrison
| Conservative
|-
|
| 2010
| colspan="2" | Constituency abolished: see South West Wiltshire and Chippenham
|}