This is a list of parliamentary by-elections in the United Kingdom held between 1806 and 1818, with the names of the previous incumbent and the victor in the by-election.
In the absence of a comprehensive and reliable source, for party and factional alignments in this period, no attempt is made to define them in this article. The House of Commons: 1790-1820 provides some guidance to the complex and shifting political relationships, but it is significant that the compilers of that work make no attempt to produce a definitive list of each member's allegiances.
Resignations
Where the cause of by-election is given as "resignation", this indicates that the incumbent was appointed on his own request to an "office of profit under the Crown". Offices used, in this period, were the Stewards of the Chiltern Hundreds or the Manor of East Hendred and the Escheators of Munster or Ulster. These appointments are made as a constitutional device for leaving the House of Commons, whose Members are not permitted to resign. If the vacancy was caused by appointment to another office then this office is noted in brackets.
By-elections The c/u column denotes whether the by-election was a contested poll or an unopposed return. If the winner was re-elected, at the next general election and any intermediate by-elections, this is indicated by an * following the c or u. In a few cases the winner was elected at the next general election but had not been re-elected in a by-election after the one noted. In those cases no * symbol is used.
3rd Parliament (1806–1807)
Date Constituency c/u Former incumbent Winner Cause10 January 1807 Haslemere u* Viscount Garlies Robert Plumer Ward Succession to a peerage10 January 1807Stockbridge u Joseph Foster Barham Sir John Fleming Leicester Chose to sit for Okehampton12 January 1807 Eye u William Cornwallis James Cornwallis Resignation14 January 1807 Enniskillen u Nathaniel Sneyd Richard Henry Alexander Bennet Chose to sit for County Cavan14 January 1807 Minehead u* Sir John Lethbridge John Fownes Luttrell Resignation15 January 1807 Mitchell u Sir Christopher Hawkins Sir Arthur Wellesley Chose to sit for GrampoundFrederick William Trench Henry Conyngham Montgomery Resignation16 January 1807 Helston u Nicholas Vansittart Thomas Brand Chose to sit for Old Sarum17 January 1807 Cockermouth u John Lowther Lord Binning Chose to sit for Cumberland17 January 1807 Tralee u Maurice Fitzgerald Samuel Boddington Chose to sit for County Kerry 20 January 1807 Dundalk u* John Metge Josias Porcher Resignation21 January 1807 Bletchingley u Josias Porcher John Alexander Bannerman Resignation to contest Dundalk21 January 1807 St Mawes u* Sir John Newport William Shipley Chose to sit for Waterford City24 January 1807 Lostwithiel u William Dickinson Charles CockerellChose to sit for Somerset26 January 1807Midhurst u John Smith Henry Watkin Williams WynnChose to sit for NottinghamWilliam Wickham William Conyngham Plunket Chose to sit for Callington27 January 1807 Arundel u Francis John Wilder The Lord Lecale Chose to sit for Horsham27 January 1807Heytesbury u* Charles Abbot Charles MooreChose to sit for Oxford Universityu Sir William Pierce Ashe A'Court Michael SymesResignation29 January 1807 Sussex u* Charles Lennox Charles William Wyndham Succession to a peerage31 January 1807 Dungannon u George Knox Viscount HamiltonChose to sit for Dublin University2 February 1807 Canterbury u James Simmons Samuel Elias Sawbridge Death4 February 1807 Coleraine u* Sir George Fitzgerald Hill Walter Jones Chose to sit for Londonderry City7 February 1807 Plympton Erle u Sir Stephen Lushington William Assheton Harbord Death17 February 1807 Worcester c* Henry Bromley William Gordon Resignation Derby u Edward Coke Thomas William Coke Resignation to contest Norfolk4 March 1807Norfolk u* Thomas William Coke Sir Jacob Henry Astley Void Electionu William Windham Edward CokeVoid Election 9 March 1807 Harwich u William Henry FremantleJames AdamsChose to sit for Saltash 13 March 1807 County Armagh u* Lord AchesonWilliam Brownlow Succeeded to an Irish peerage23 March 1807 BuckinghamuSir William Young Sir John Borlase Warren Resignation (Governor of Tobago)31 March 1807 Carrickfergus c* Lord Spencer Stanley Chichester James Craig Resignation1 April 1807 Newtown u George Canning George Canning Foreign Secretary1 April 1807 Northamptonu*Spencer Perceval Spencer Perceval Chancellor of the Exchequer2 April 1807 Calneu* Osborne Markham Henry Smith Resignation (Commissioner of Barrack Master General)3 April 1807 Haslemere u* Charles LongCharles Long Joint Paymaster of the Forces3 April 1807 Plympton Erleu*Viscount CastlereaghViscount Castlereagh Secretary of State for War and the Colonies4 April 1807 Bere Alston u* Lord Lovaine Lord Lovaine Commissioner of the Board of Control6 April 1807 Monmouth Boroughs u* Lord Charles Henry Somerset Lord Charles Henry Somerset Joint Paymaster of the Forces9 April 1807 Buckinghamshireu*Marquess of Titchfield Marquess of Titchfield Junior Lord of the Treasury13 April 1807Edinburghshireu*Robert Saunders DundasRobert Saunders Dundas President of the Board of Control13 April 1807Queen's Countyu*William Wellesley PoleWilliam Wellesley PoleClerk of the Ordnance14 April 1807Dorchesteru*Cropley AshleyCropley AshleyClerk of the Deliveries of the Ordnance15 April 1807Haslemereu*Robert Plumer WardRobert Plumer WardLord of the Admiralty15 April 1807Liskeardu*William EliotWilliam EliotJunior Lord of the Treasury16 Apr 1807Weymouth & Melcombe Regisu*Sir James PulteneySir James PulteneySecretary at War17 April 1807Christchurchu*George RoseGeorge RoseTreasurer of the NavyWilliam Sturges BourneWilliam Sturges BourneJunior Lord of the Treasury17 April 1807West Looeu*James BullerJames BullerLord of the Admiralty18 April 1807Great BedwynuViscount StopfordSir Vicary Gibbs Treasurer of the Household20 April 1807Eyeu*Marquess of HuntlyHenry Wellesley Elevated to the House of Lords through a Writ of acceleration20 April 1807Marlboroughu*Earl of DalkeithViscount Stopford Elevated to the House of Lords through a Writ of acceleration21 April 1807MitchelluSir Arthur WellesleySir Arthur WellesleyChief Secretary for Ireland1 May 1807Dumfriesshireu*William Johnstone HopeWilliam Johnstone HopeNaval Lord
4th Parliament (1807–1812)