List of United Kingdom by-elections (1900–1918)

This is a list of parliamentary by-elections in the United Kingdom held between 1900 and 1918, with the names of the incumbent and victor and their respective parties. Where seats changed political party at the election, the result is highlighted: pink for a Labour (including Labour Representation Committee) gain, light blue for a Conservative (including Liberal Unionist, Irish Unionist and Scottish Unionist) gain, orange for a Liberal (including Liberal-Labour) gain, green for a Sinn Féin gain, light green for an Irish Parliamentary Party gain and grey for any other gain.

Resignations
Where the cause of by-election is given as "resignation" or "seeks re-election", this indicates that the incumbent was appointed on his own request to an "office of profit under the Crown", either the Steward of the Chiltern Hundreds or the Steward of the Manor of Northstead. These appointments are made as a constitutional device for leaving the House of Commons, whose Members are not permitted to resign.

By-elections
{| class="wikitable"
 * colspan=10|

30th Parliament (August 1914 – 1918)
!By-election !! Date !! Incumbent !! colspan=2 | Party !! Winner !! colspan=2 | Party !! Cause
 * Wilton
 * 6 November 1918
 * Sir Charles Bathurst
 * Hugh Morrison
 * Elevation
 * Prestwich
 * 28 October 1918
 * Hon. Oswald Cawley
 * Austin Hopkinson
 * Killed in action
 * South Shields
 * 28 October 1918
 * Cecil Cochrane
 * Havelock Wilson
 * Resignation
 * Elgin Burghs
 * 25 October 1918
 * John Sutherland
 * Charles Barrie
 * Death
 * Mid Norfolk
 * 23 October 1918
 * William Lewis Boyle
 * Neville Jodrell
 * Death
 * Bath
 * 15 October 1918
 * Lord Alexander Thynne
 * Charles Foxcroft
 * Killed in action
 * St George's, Hanover Square
 * 4 October 1918
 * Sir George Reid
 * Sir Newton Moore
 * Death
 * Banbury
 * 24 September 1918
 * Hon Sir Eustace Fiennes
 * Sir Rhys Williams
 * Governor of the Seychelles
 * Canterbury
 * 9 August 1918
 * Francis Bennett-Goldney
 * George Knox Anderson
 * Death
 * East Grinstead
 * 29 July 1918
 * Henry Cautley
 * Henry Cautley
 * Recorder of Sunderland
 * Fareham
 * 18 July 1918
 * Sir Arthur Lee
 * John Humphrey Davidson
 * Elevation
 * Manchester North East
 * 16 July 1918
 * J. R. Clynes
 * J. R. Clynes
 * Food Controller
 * Finsbury East
 * 16 July 1918
 * Joseph Allen Baker
 * Harry Cotton
 * Death
 * Clapham
 * 21 June 1918
 * Denison Faber
 * Harry Greer
 * Resignation
 * - bgcolor=#97CC97
 * East Cavan
 * 20 June 1918
 * Samuel Young
 * Arthur Griffith
 * Death
 * Bridgwater
 * 18 June 1918
 * Robert Sanders
 * Robert Sanders
 * Treasurer of the Household
 * Gravesend
 * 7 June 1918
 * Sir Gilbert Parker
 * Alexander Richardson
 * Resignation
 * Wansbeck
 * 28 May 1918
 * Charles Fenwick
 * Robert Mason
 * Death
 * Newcastle-upon-Tyne
 * 13 May 1918
 * Edward Shortt
 * Edward Shortt
 * Chief Secretary for Ireland
 * Exeter
 * 7 May 1918
 * Henry Duke
 * Sir Robert Newman
 * Lord Justice of Appeal
 * Ross
 * 4 May 1918
 * Percy Clive
 * Charles Pulley
 * Killed in action
 * Keighley
 * 26 April 1918
 * Sir Swire Smith
 * William Somervell
 * Death
 * Birmingham West
 * 25 April 1918
 * Austen Chamberlain
 * Austen Chamberlain
 * Minister without Portfolio
 * - bgcolor=#97CC97
 * Tullamore
 * 19 April 1918
 * Edward John Graham
 * Dr Patrick McCartan
 * Death
 * East Tyrone
 * 3 April 1918
 * William Redmond
 * Thomas Harbison
 * Resignation in order to contest Waterford
 * Manchester South
 * 22 March 1918
 * Philip Glazebrook
 * Robert Stoker
 * Killed in action
 * Waterford City
 * 22 March 1918
 * John Redmond
 * William Redmond
 * Death
 * South Armagh
 * 2 February 1918
 * Charles O'Neill
 * Patrick Donnelly
 * Death
 * Prestwich
 * 31 January 1918
 * Sir Frederick Cawley
 * Hon. Oswald Cawley
 * Elevation
 * Mid Armagh
 * 23 January 1918
 * Sir John Lonsdale
 * James Rolston Lonsdale
 * Resignation
 * Southampton
 * 19 December 1917
 * William Dudley Ward
 * William Dudley Ward
 * Vice-Chamberlain of the Household
 * Wisbech
 * 14 December 1917
 * Hon. Neil Primrose
 * Colin Coote
 * Died of wounds
 * North Armagh
 * 22 November 1917
 * Sir William Moore
 * William Allen
 * Judge of the High Court of Justice in Ireland
 * - bgcolor=#c0c0c0
 * Salford North
 * 2 November 1917
 * Sir William Byles
 * Ben Tillett
 * Death
 * Basingstoke
 * 25 October 1917
 * Arthur Salter
 * Sir Auckland Geddes
 * High Court judge
 * Spalding
 * 25 October 1917
 * Hon. Francis McLaren
 * Hon. George Peel
 * Killed in action
 * Islington East
 * 23 October 1917
 * Sir George Heynes Radford
 * Edward Smallwood
 * Death
 * Dublin University
 * 5 October 1917
 * Arthur Warren Samuels
 * Arthur Warren Samuels
 * Solicitor-General for Ireland
 * Norwich
 * 26 August 1917
 * George Henry Roberts
 * George Henry Roberts
 * Minister of Labour
 * Edinburgh and St Andrews Universities
 * 10 August 1917
 * Sir Christopher Johnston
 * Sir William Cheyne
 * Senator of the College of Justice
 * - bgcolor=#97CC97
 * Kilkenny City
 * 10 August 1917
 * Patrick O'Brien
 * W. T. Cosgrave
 * Death
 * Dundee
 * 30 July 1917
 * Winston Churchill
 * Winston Churchill
 * Minister of Munitions
 * Chesterton
 * 27 July 1917
 * Edwin Samuel Montagu
 * Edwin Samuel Montagu
 * Secretary of State for India
 * Cambridge
 * 25 July 1917
 * Almeric Paget
 * Sir Eric Geddes
 * Resignation
 * South Monmouthshire
 * 13 July 1917
 * Sir Ivor Herbert
 * Sir Abraham Garrod Thomas
 * Elevation
 * - bgcolor=#97CC97
 * East Clare
 * 10 July 1917
 * Willie Redmond
 * Éamon de Valera
 * Killed in action
 * South Dublin
 * 6 July 1917
 * William Francis Cotton
 * Michael Hearn
 * Death
 * Fulham
 * 3 July 1917
 * William Hayes Fisher
 * William Hayes Fisher
 * President of the Local Government Board
 * Belfast South
 * 2 July 1917
 * James Chambers
 * William Arthur Lindsay
 * Death
 * Liverpool Abercromby
 * 28 June 1917
 * Richard Chaloner
 * Lord Stanley
 * Elevation
 * Epping
 * 28 June 1917
 * Amelius Lockwood
 * Richard Colvin
 * Elevation
 * Henley
 * 20 June 1917
 * Valentine Fleming
 * Robert Hermon-Hodge
 * Killed in action
 * Edinburgh South
 * 13 May 1917
 * Hon. Charles Henry Lyell
 * Sir Edward Parrott
 * Resignation
 * - bgcolor=#97CC97
 * South Longford
 * 10 May 1917
 * John Phillips
 * Joseph McGuinness
 * Death
 * Ealing
 * 30 April 1917
 * Herbert Nield
 * Herbert Nield
 * Recorder of York
 * Belfast South
 * 9 April 1917
 * James Chambers
 * James Chambers
 * Solicitor-General for Ireland
 * Aberdeen South
 * 3 April 1917
 * George Esslemont
 * Sir John Fleming
 * Resignation
 * Oxford
 * 30 March 1917
 * Viscount Valentia
 * John Marriott
 * Elevation to a UK Peerage
 * Stockton-on-Tees
 * 20 March 1917
 * Jonathan Samuel
 * Bertrand Watson
 * Death
 * Tamworth
 * 23 February 1917
 * Francis Newdigate
 * Henry Wilson-Fox
 * Governor of Tasmania
 * West Perthshire
 * 21 February 1917
 * John Stewart-Murray
 * Archibald Stirling
 * Succession
 * Rossendale
 * 13 February 1917
 * Lewis Harcourt
 * Sir John Maden
 * Elevation
 * Rotherham
 * 5 February 1917
 * Joseph Pease
 * Arthur Richardson
 * Elevation
 * Dublin University
 * 5 February 1917
 * James Campbell
 * Arthur Warren Samuels
 * Lord Chief Justice of Ireland
 * - bgcolor=#97CC97
 * North Roscommon
 * 3 February 1917
 * James Joseph O'Kelly
 * Count George Noble Plunkett
 * Death
 * Inverness-shire
 * 2 January 1917
 * Sir John Dewar
 * Thomas Brash Morison
 * Elevation
 * Edinburgh and St Andrews Universities
 * 29 December 1916
 * Sir Robert Finlay
 * Christopher Johnston
 * Hereditary Peerage on appointment as Lord High Chancellor of Great Britain
 * Derby
 * 29 December 1916
 * Sir Thomas Roe
 * Sir William Collins
 * Elevation
 * Whitechapel
 * 28 December 1916
 * Sir Stuart Samuel
 * James Kiley
 * Resignation
 * - bgcolor=FFCC66
 * Sheffield Hallam
 * 23 December 1916
 * Charles Stuart-Wortley
 * H. A. L. Fisher
 * Elevation
 * Ashton-under-Lyne
 * 23 December 1916
 * Sir Max Aitken
 * Sir Albert Stanley
 * Elevation
 * Hornsey
 * 6 December 1916
 * Lawrence Dundas
 * Kennedy Jones
 * Governor of Bengal
 * West Cork
 * 15 November 1916
 * James Gilhooly
 * Daniel O'Leary
 * Death
 * North Fermanagh
 * 27 October 1916
 * Godfrey Fetherstonhaugh
 * Edward Archdale
 * Resignation
 * Winchester
 * 19 October 1916
 * Hon. Guy Baring
 * Hon. Douglas Carnegie
 * Killed in action
 * St Pancras West
 * 16 October 1916
 * Felix Cassel
 * Richard Barnett
 * Resignation
 * North Ayrshire
 * 11 October 1916
 * Duncan Campbell
 * Aylmer Hunter-Weston
 * Death
 * Mansfield
 * 20 September 1916
 * Sir Arthur Markham
 * Sir Charles Seely
 * Death
 * Abingdon
 * 29 August 1916
 * Hon. Harold Henderson
 * Archie Loyd
 * Resignation
 * Colne Valley
 * 25 August 1916
 * Rev. Charles Leach
 * Frederick Mallalieu
 * Member certified as insane
 * Berwick-upon-Tweed
 * 16 August 1916
 * Sir Edward Grey
 * Sir Francis Blake
 * Elevation
 * Bodmin
 * 15 August 1916
 * Sir Reginald Pole-Carew
 * Charles Hanson
 * Resignation
 * Exeter
 * 7 August 1916
 * Henry Duke
 * Henry Duke
 * Chief Secretary for Ireland
 * Berwickshire
 * 18 July 1916
 * Harold Tennant
 * Harold Tennant
 * Secretary for Scotland
 * Widnes
 * 22 May 1916
 * William Walker
 * William Walker
 * Seeking re-election
 * South Londonderry
 * 22 May 1916
 * John Gordon
 * Denis Henry
 * Resignation (Justice of the High Court of Ireland)
 * Tewkesbury
 * 16 May 1916
 * Michael Hicks Beach
 * William Frederick Hicks-Beach
 * Died of wounds
 * Ossory
 * 28 April 1916
 * William Delany
 * John Lalor Fitzpatrick
 * Death
 * Dublin University
 * 25 April 1916
 * James Campbell
 * James Campbell
 * Attorney-General for Ireland
 * Wimbledon
 * 19 April 1916
 * Henry Chaplin
 * Sir Stuart Coats
 * Resignation
 * Hyde
 * 30 March 1916
 * Francis Neilson
 * Thomas Jacobsen
 * Resignation
 * Harborough
 * 23 March 1916
 * John William Logan
 * Percy Harris
 * Resignation
 * South Shields
 * 18 March 1916
 * Russell Rea
 * Cecil Cochrane
 * Death
 * - bgcolor=#c0c0c0
 * Hertford
 * 9 March 1916
 * Sir John Rolleston
 * Noel Pemberton Billing
 * Resignation
 * Cockermouth
 * 2 March 1916
 * Sir Wilfrid Lawson
 * Joseph Bliss
 * Resignation
 * Droitwich
 * 29 February 1916
 * Hon. John Lyttelton
 * Herbert Whiteley
 * Resignation
 * Chester
 * 29 February 1916
 * Robert Yerburgh
 * Sir Owen Philipps
 * Resignation
 * Bolton
 * 29 February 1916
 * Thomas Taylor
 * William Edge
 * Resignation
 * South Tyrone
 * 28 February 1916
 * Andrew Horner
 * William Coote
 * Death
 * North Louth
 * 24 February 1916
 * Augustine Roche
 * Patrick Whitty
 * Death
 * Liverpool East Toxteth
 * 21 February 1916
 * Edward Marshall Hall
 * James Stuart Rankin
 * Recorder of Guildford
 * Rotherham
 * 26 January 1916
 * Joseph Pease
 * Joseph Pease
 * Postmaster-General
 * Mile End
 * 25 January 1916
 * Hon. Harry Levy-Lawson
 * Warwick Brookes
 * Succession
 * Bradford Central
 * 21 January 1916
 * Sir George Scott Robertson
 * James Hill
 * Death
 * Chesterton
 * 20 January 1916
 * Edwin Samuel Montagu
 * Edwin Samuel Montagu
 * Chancellor of the Duchy of Lancaster
 * North West Staffordshire
 * 17 January 1916
 * Albert Stanley
 * Samuel Finney
 * Death
 * Portsmouth
 * 15 January 1916
 * Lord Charles Beresford
 * Hon. Sir Hedworth Meux
 * Elevation
 * St George, Hanover Square
 * 11 January 1916
 * Sir Alexander Henderson
 * Sir George Reid
 * Elevation
 * Newington West
 * 10 January 1916
 * Cecil Norton
 * James Daniel Gilbert
 * Elevation
 * Cleveland
 * 9 December 1915
 * Herbert Samuel
 * Herbert Samuel
 * Chancellor of the Duchy of Lancaster
 * Tiverton
 * 30 November 1915
 * Hon. William Walrond
 * Charles Carew
 * Died of wounds
 * - bgcolor=#c0c0c0
 * Merthyr Tydfil
 * 25 November 1915
 * Keir Hardie
 * Charles Stanton
 * Death
 * St Austell
 * 24 November 1915
 * Thomas Agar-Robartes
 * Sir Francis Layland-Barratt
 * Died of wounds
 * St Helens
 * 24 November 1915
 * Rigby Swift
 * Rigby Swift
 * Recorder of Wigan
 * Kingston
 * 16 November 1915
 * George Cave
 * George Cave
 * Solicitor General for England and Wales
 * Cardiff
 * 12 November 1915
 * Lord Ninian Crichton-Stuart
 * James Cory
 * Killed in action
 * Uxbridge
 * 10 November 1915
 * Hon. Charles Thomas Mills
 * Hon. Arthur Mills
 * Killed in action
 * Heywood
 * 10 November 1915
 * Harold Thomas Cawley
 * Albert Illingworth
 * Killed in action
 * Appleby
 * 27 October 1915
 * Sir Lancelot Sanderson
 * Cecil Lowther
 * High Court judge
 * Dublin Harbour
 * 1 October 1915
 * William Abraham
 * Alfie Byrne
 * Death
 * Glasgow Central
 * 16 July 1915
 * Charles Dickson
 * John MacLeod
 * Lord Justice Clerk
 * Arfon
 * 6 July 1915
 * William Jones
 * Griffith Rees
 * Death
 * Keighley
 * 29 June 1915
 * Sir Stanley Buckmaster
 * Sir Swire Smith
 * Hereditary Peerage on appointment as Lord High Chancellor of Great Britain
 * North Tipperary
 * 17 June 1915
 * Dr John Joseph Esmonde
 * Sir John Esmonde
 * Death
 * Dublin College Green
 * 11 June 1915
 * Joseph Nannetti
 * John Dillon Nugent
 * Death
 * Preston
 * 9 June 1915
 * Alfred Tobin
 * Urban H. Broughton
 * County Court judge
 * Kilmarnock Burghs
 * 28 May 1915
 * William Glynne Gladstone
 * Hon. Alexander Shaw
 * Killed in action
 * Mid Durham
 * 29 April 1915
 * John Wilson
 * Samuel Galbraith
 * Death
 * Carmarthen Boroughs
 * 17 March 1915
 * W. Llewelyn Williams
 * W. Llewelyn Williams
 * Recorder of Cardiff
 * Maidstone
 * 22 February 1915
 * Charles Vane-Tempest-Stewart
 * Carlyon Bellairs
 * Succession
 * Mid Antrim
 * 17 February 1915
 * Hon. Arthur O'Neill
 * Hon. Hugh O'Neill
 * Killed in action
 * Liverpool Kirkdale
 * 15 February 1915
 * Gerald Kyffin-Taylor
 * De Fonblanque Pennefather
 * Resignation
 * Saffron Walden
 * 13 February 1915
 * Cecil Beck
 * Cecil Beck
 * Commissioner of the Treasury
 * Chesterton
 * 13 February 1915
 * Edwin Samuel Montagu
 * Edwin Samuel Montagu
 * Chancellor of the Duchy of Lancaster
 * Wigtownshire
 * 12 February 1915
 * John Dalrymple
 * Hon. Hew Dalrymple
 * Succession
 * Thirsk and Malton
 * 12 February 1915
 * Charles Duncombe
 * Edmund Turton
 * Succession
 * Howdenshire
 * 10 February 1915
 * Henry Harrison-Broadley
 * Hon. Stanley Jackson
 * Death
 * Shipley
 * 9 February 1915
 * Percy Illingworth
 * Oswald Partington
 * Death (food poisoning)
 * Scarborough
 * 9 February 1915
 * Walter Rea
 * Walter Rea
 * Commissioner of the Treasury
 * Swansea District
 * 6 February 1915
 * David Brynmor Jones
 * Thomas Jeremiah Williams
 * Master in Lunacy
 * Norwich
 * 6 February 1915
 * Sir Frederick Low
 * Hilton Young
 * High Court judge
 * Sheffield Attercliffe
 * 28 December 1914
 * Joseph Pointer
 * William Crawford Anderson
 * Death
 * - bgcolor=#c0c0c0
 * Tullamore
 * 8 December 1914
 * Edmund Haviland-Burke
 * Edward John Graham
 * Death
 * East Galway
 * 4 December 1914
 * John Roche
 * James Cosgrave
 * Death
 * Londonderry City
 * 30 November 1914
 * David Cleghorn Hogg
 * Sir James Brown Dougherty
 * Death
 * The Hartlepools
 * 22 September 1914
 * Sir Stephen Furness
 * Sir Walter Runciman
 * Death
 * Bolton
 * 22 September 1914
 * Alfred Gill
 * Robert Tootill
 * Death
 * West Wicklow
 * 20 August 1914
 * Edward O'Kelly
 * John Thomas Donovan
 * Death
 * Swansea District
 * 13 August 1914
 * Sir David Brynmor Jones
 * Sir David Brynmor Jones
 * Recorder of Cardiff
 * colspan=9|
 * Joseph Bliss
 * Resignation
 * Droitwich
 * 29 February 1916
 * Hon. John Lyttelton
 * Herbert Whiteley
 * Resignation
 * Chester
 * 29 February 1916
 * Robert Yerburgh
 * Sir Owen Philipps
 * Resignation
 * Bolton
 * 29 February 1916
 * Thomas Taylor
 * William Edge
 * Resignation
 * South Tyrone
 * 28 February 1916
 * Andrew Horner
 * William Coote
 * Death
 * North Louth
 * 24 February 1916
 * Augustine Roche
 * Patrick Whitty
 * Death
 * Liverpool East Toxteth
 * 21 February 1916
 * Edward Marshall Hall
 * James Stuart Rankin
 * Recorder of Guildford
 * Rotherham
 * 26 January 1916
 * Joseph Pease
 * Joseph Pease
 * Postmaster-General
 * Mile End
 * 25 January 1916
 * Hon. Harry Levy-Lawson
 * Warwick Brookes
 * Succession
 * Bradford Central
 * 21 January 1916
 * Sir George Scott Robertson
 * James Hill
 * Death
 * Chesterton
 * 20 January 1916
 * Edwin Samuel Montagu
 * Edwin Samuel Montagu
 * Chancellor of the Duchy of Lancaster
 * North West Staffordshire
 * 17 January 1916
 * Albert Stanley
 * Samuel Finney
 * Death
 * Portsmouth
 * 15 January 1916
 * Lord Charles Beresford
 * Hon. Sir Hedworth Meux
 * Elevation
 * St George, Hanover Square
 * 11 January 1916
 * Sir Alexander Henderson
 * Sir George Reid
 * Elevation
 * Newington West
 * 10 January 1916
 * Cecil Norton
 * James Daniel Gilbert
 * Elevation
 * Cleveland
 * 9 December 1915
 * Herbert Samuel
 * Herbert Samuel
 * Chancellor of the Duchy of Lancaster
 * Tiverton
 * 30 November 1915
 * Hon. William Walrond
 * Charles Carew
 * Died of wounds
 * - bgcolor=#c0c0c0
 * Merthyr Tydfil
 * 25 November 1915
 * Keir Hardie
 * Charles Stanton
 * Death
 * St Austell
 * 24 November 1915
 * Thomas Agar-Robartes
 * Sir Francis Layland-Barratt
 * Died of wounds
 * St Helens
 * 24 November 1915
 * Rigby Swift
 * Rigby Swift
 * Recorder of Wigan
 * Kingston
 * 16 November 1915
 * George Cave
 * George Cave
 * Solicitor General for England and Wales
 * Cardiff
 * 12 November 1915
 * Lord Ninian Crichton-Stuart
 * James Cory
 * Killed in action
 * Uxbridge
 * 10 November 1915
 * Hon. Charles Thomas Mills
 * Hon. Arthur Mills
 * Killed in action
 * Heywood
 * 10 November 1915
 * Harold Thomas Cawley
 * Albert Illingworth
 * Killed in action
 * Appleby
 * 27 October 1915
 * Sir Lancelot Sanderson
 * Cecil Lowther
 * High Court judge
 * Dublin Harbour
 * 1 October 1915
 * William Abraham
 * Alfie Byrne
 * Death
 * Glasgow Central
 * 16 July 1915
 * Charles Dickson
 * John MacLeod
 * Lord Justice Clerk
 * Arfon
 * 6 July 1915
 * William Jones
 * Griffith Rees
 * Death
 * Keighley
 * 29 June 1915
 * Sir Stanley Buckmaster
 * Sir Swire Smith
 * Hereditary Peerage on appointment as Lord High Chancellor of Great Britain
 * North Tipperary
 * 17 June 1915
 * Dr John Joseph Esmonde
 * Sir John Esmonde
 * Death
 * Dublin College Green
 * 11 June 1915
 * Joseph Nannetti
 * John Dillon Nugent
 * Death
 * Preston
 * 9 June 1915
 * Alfred Tobin
 * Urban H. Broughton
 * County Court judge
 * Kilmarnock Burghs
 * 28 May 1915
 * William Glynne Gladstone
 * Hon. Alexander Shaw
 * Killed in action
 * Mid Durham
 * 29 April 1915
 * John Wilson
 * Samuel Galbraith
 * Death
 * Carmarthen Boroughs
 * 17 March 1915
 * W. Llewelyn Williams
 * W. Llewelyn Williams
 * Recorder of Cardiff
 * Maidstone
 * 22 February 1915
 * Charles Vane-Tempest-Stewart
 * Carlyon Bellairs
 * Succession
 * Mid Antrim
 * 17 February 1915
 * Hon. Arthur O'Neill
 * Hon. Hugh O'Neill
 * Killed in action
 * Liverpool Kirkdale
 * 15 February 1915
 * Gerald Kyffin-Taylor
 * De Fonblanque Pennefather
 * Resignation
 * Saffron Walden
 * 13 February 1915
 * Cecil Beck
 * Cecil Beck
 * Commissioner of the Treasury
 * Chesterton
 * 13 February 1915
 * Edwin Samuel Montagu
 * Edwin Samuel Montagu
 * Chancellor of the Duchy of Lancaster
 * Wigtownshire
 * 12 February 1915
 * John Dalrymple
 * Hon. Hew Dalrymple
 * Succession
 * Thirsk and Malton
 * 12 February 1915
 * Charles Duncombe
 * Edmund Turton
 * Succession
 * Howdenshire
 * 10 February 1915
 * Henry Harrison-Broadley
 * Hon. Stanley Jackson
 * Death
 * Shipley
 * 9 February 1915
 * Percy Illingworth
 * Oswald Partington
 * Death (food poisoning)
 * Scarborough
 * 9 February 1915
 * Walter Rea
 * Walter Rea
 * Commissioner of the Treasury
 * Swansea District
 * 6 February 1915
 * David Brynmor Jones
 * Thomas Jeremiah Williams
 * Master in Lunacy
 * Norwich
 * 6 February 1915
 * Sir Frederick Low
 * Hilton Young
 * High Court judge
 * Sheffield Attercliffe
 * 28 December 1914
 * Joseph Pointer
 * William Crawford Anderson
 * Death
 * - bgcolor=#c0c0c0
 * Tullamore
 * 8 December 1914
 * Edmund Haviland-Burke
 * Edward John Graham
 * Death
 * East Galway
 * 4 December 1914
 * John Roche
 * James Cosgrave
 * Death
 * Londonderry City
 * 30 November 1914
 * David Cleghorn Hogg
 * Sir James Brown Dougherty
 * Death
 * The Hartlepools
 * 22 September 1914
 * Sir Stephen Furness
 * Sir Walter Runciman
 * Death
 * Bolton
 * 22 September 1914
 * Alfred Gill
 * Robert Tootill
 * Death
 * West Wicklow
 * 20 August 1914
 * Edward O'Kelly
 * John Thomas Donovan
 * Death
 * Swansea District
 * 13 August 1914
 * Sir David Brynmor Jones
 * Sir David Brynmor Jones
 * Recorder of Cardiff
 * colspan=9|
 * Recorder of Cardiff
 * Maidstone
 * 22 February 1915
 * Charles Vane-Tempest-Stewart
 * Carlyon Bellairs
 * Succession
 * Mid Antrim
 * 17 February 1915
 * Hon. Arthur O'Neill
 * Hon. Hugh O'Neill
 * Killed in action
 * Liverpool Kirkdale
 * 15 February 1915
 * Gerald Kyffin-Taylor
 * De Fonblanque Pennefather
 * Resignation
 * Saffron Walden
 * 13 February 1915
 * Cecil Beck
 * Cecil Beck
 * Commissioner of the Treasury
 * Chesterton
 * 13 February 1915
 * Edwin Samuel Montagu
 * Edwin Samuel Montagu
 * Chancellor of the Duchy of Lancaster
 * Wigtownshire
 * 12 February 1915
 * John Dalrymple
 * Hon. Hew Dalrymple
 * Succession
 * Thirsk and Malton
 * 12 February 1915
 * Charles Duncombe
 * Edmund Turton
 * Succession
 * Howdenshire
 * 10 February 1915
 * Henry Harrison-Broadley
 * Hon. Stanley Jackson
 * Death
 * Shipley
 * 9 February 1915
 * Percy Illingworth
 * Oswald Partington
 * Death (food poisoning)
 * Scarborough
 * 9 February 1915
 * Walter Rea
 * Walter Rea
 * Commissioner of the Treasury
 * Swansea District
 * 6 February 1915
 * David Brynmor Jones
 * Thomas Jeremiah Williams
 * Master in Lunacy
 * Norwich
 * 6 February 1915
 * Sir Frederick Low
 * Hilton Young
 * High Court judge
 * Sheffield Attercliffe
 * 28 December 1914
 * Joseph Pointer
 * William Crawford Anderson
 * Death
 * - bgcolor=#c0c0c0
 * Tullamore
 * 8 December 1914
 * Edmund Haviland-Burke
 * Edward John Graham
 * Death
 * East Galway
 * 4 December 1914
 * John Roche
 * James Cosgrave
 * Death
 * Londonderry City
 * 30 November 1914
 * David Cleghorn Hogg
 * Sir James Brown Dougherty
 * Death
 * The Hartlepools
 * 22 September 1914
 * Sir Stephen Furness
 * Sir Walter Runciman
 * Death
 * Bolton
 * 22 September 1914
 * Alfred Gill
 * Robert Tootill
 * Death
 * West Wicklow
 * 20 August 1914
 * Edward O'Kelly
 * John Thomas Donovan
 * Death
 * Swansea District
 * 13 August 1914
 * Sir David Brynmor Jones
 * Sir David Brynmor Jones
 * Recorder of Cardiff
 * colspan=9|
 * Death
 * - bgcolor=#c0c0c0
 * Tullamore
 * 8 December 1914
 * Edmund Haviland-Burke
 * Edward John Graham
 * Death
 * East Galway
 * 4 December 1914
 * John Roche
 * James Cosgrave
 * Death
 * Londonderry City
 * 30 November 1914
 * David Cleghorn Hogg
 * Sir James Brown Dougherty
 * Death
 * The Hartlepools
 * 22 September 1914
 * Sir Stephen Furness
 * Sir Walter Runciman
 * Death
 * Bolton
 * 22 September 1914
 * Alfred Gill
 * Robert Tootill
 * Death
 * West Wicklow
 * 20 August 1914
 * Edward O'Kelly
 * John Thomas Donovan
 * Death
 * Swansea District
 * 13 August 1914
 * Sir David Brynmor Jones
 * Sir David Brynmor Jones
 * Recorder of Cardiff
 * colspan=9|
 * Robert Tootill
 * Death
 * West Wicklow
 * 20 August 1914
 * Edward O'Kelly
 * John Thomas Donovan
 * Death
 * Swansea District
 * 13 August 1914
 * Sir David Brynmor Jones
 * Sir David Brynmor Jones
 * Recorder of Cardiff
 * colspan=9|
 * Swansea District
 * 13 August 1914
 * Sir David Brynmor Jones
 * Sir David Brynmor Jones
 * Recorder of Cardiff
 * colspan=9|
 * Recorder of Cardiff
 * colspan=9|
 * colspan=9|

30th Parliament (December 1910 – July 1914)
!By-election !! Date !! Incumbent !! colspan=2 | Party !! Winner !! colspan=2 | Party !! Cause
 * North Galway
 * 21 July 1914
 * Richard Hazleton
 * Richard Hazleton
 * Seeks re-election
 * East Worcestershire
 * 16 July 1914
 * Austen Chamberlain
 * Frederick Leverton Harris
 * Resignation in order to fight Birmingham West
 * Birmingham West
 * 14 July 1914
 * Joseph Chamberlain
 * Austen Chamberlain
 * Death
 * Oxford University
 * 30 June 1914
 * Sir William Anson
 * Rowland Prothero
 * Death
 * Brighton
 * 29 June 1914
 * Hon. John Gordon
 * Charles Thomas-Stanford
 * Resignation
 * - bgcolor=lightblue
 * Ipswich
 * 23 May 1914
 * Silvester Horne
 * John Ganzoni
 * Death
 * - bgcolor=lightblue
 * North East Derbyshire
 * 20 May 1914
 * W. E. Harvey
 * Harland Bowden
 * Death
 * Great Grimsby
 * 12 May 1914
 * Sir George Doughty
 * Thomas Tickler
 * Death
 * East Fife
 * 8 April 1914
 * H. H. Asquith
 * H. H. Asquith
 * Secretary of State for War
 * Belfast East
 * 6 April 1914
 * Robert McMordie
 * Robert Sharman-Crawford
 * Death
 * - bgcolor=lightblue
 * Leith Burghs
 * 26 February 1914
 * Ronald Munro-Ferguson
 * George Welsh Currie
 * Governor General of Australia
 * Poplar
 * 19 February 1914
 * Sydney Buxton
 * Alfred William Yeo
 * Governor-General of the Union of South Africa
 * - bgcolor=lightblue
 * Bethnal Green South West
 * 19 February 1914
 * Charles Masterman
 * Mathew Wilson
 * Chancellor of the Duchy of Lancaster
 * Cork City
 * 18 February 1914
 * William O'Brien
 * William O'Brien
 * Resigned to re-contest
 * Wycombe
 * 18 February 1914
 * Sir Charles Cripps
 * William Baring du Pré
 * Elevation
 * North West Durham
 * 30 January 1914
 * Llewellyn Atherley-Jones
 * Aneurin Williams
 * Judge of the City of London Court
 * - bgcolor=lightblue
 * South Lanarkshire
 * 12 December 1913
 * Sir Walter Menzies
 * Hon. William Watson
 * Death
 * Wick Burghs
 * 8 December 1913
 * Robert Munro
 * Robert Munro
 * Lord Advocate
 * Keighley
 * 11 November 1913
 * Sir Stanley Buckmaster
 * Sir Stanley Buckmaster
 * Solicitor General for England and Wales
 * - bgcolor=lightblue
 * Reading
 * 8 November 1913
 * Sir Rufus Isaacs
 * Leslie Orme Wilson
 * Lord Chief Justice of England and Wales
 * Linlithgowshire
 * 7 November 1913
 * Alexander Ure
 * John Pratt
 * Lord President of the Court of Session
 * North Cork
 * 4 November 1913
 * Patrick Guiney
 * John Guiney
 * Death
 * - bgcolor=FFCC66
 * Chesterfield
 * 20 August 1913
 * James Haslam
 * Barnet Kenyon
 * Death
 * St George's, Hanover Square
 * 15 July 1913
 * Alfred Lyttelton
 * Sir Alexander Henderson
 * Death
 * Leicester
 * 27 June 1913
 * Eliot Crawshay-Williams
 * Gordon Hewart
 * Resignation
 * Dover
 * 23 June 1913
 * George Wyndham
 * Vere Ponsonby
 * Death
 * Wandsworth
 * 12 June 1913
 * Sir Henry Kimber
 * Samuel Samuel
 * Resignation
 * Leix
 * 9 June 1913
 * Patrick Aloysius Meehan
 * Patrick Joseph Meehan
 * Death
 * Altrincham
 * 28 May 1913
 * John Kebty-Fletcher
 * George Hamilton
 * Resignation
 * - bgcolor=lightblue
 * Newmarket
 * 16 May 1913
 * Sir Charles Rose
 * John Denison-Pender
 * Death
 * Whitechapel
 * 30 April 1913
 * Sir Stuart Samuel
 * Sir Stuart Samuel
 * Undertook a contract for the Public Service
 * Shrewsbury
 * 22 April 1913
 * Sir Clement Hill
 * George Butler Lloyd
 * Death
 * - bgcolor=#c0c0c0
 * Kendal
 * 18 March 1913
 * Sir Josceline Bagot
 * John Weston
 * Death
 * Houghton-le-Spring
 * 18 March 1913
 * Robert Cameron
 * Thomas Wing
 * Death
 * Chorley
 * 19 February 1913
 * David Lindsay
 * Sir Henry Hibbert
 * Succession
 * East Antrim
 * 19 February 1913
 * James McCalmont
 * Robert McCalmont
 * Death
 * East Waterford
 * 15 February 1913
 * Patrick Joseph Power
 * Martin Joseph Murphy
 * Death
 * -bgcolor=FFCC66
 * Londonderry City
 * 30 January 1913
 * James Hamilton
 * David Cleghorn Hogg
 * Succession
 * Flint Boroughs
 * 21 January 1913
 * James Summers
 * Thomas Henry Parry
 * Death
 * - bgcolor=lightblue
 * Bow and Bromley
 * 26 November 1912
 * George Lansbury
 * Reginald Blair
 * Resigned to recontest on platform of women's suffrage
 * Bolton
 * 23 November 1912
 * George Harwood
 * Thomas Taylor
 * Death
 * Taunton
 * 11 November 1912
 * Hon. William Peel
 * Sir Gilbert Wills
 * Succession
 * - bgcolor=lightblue
 * Midlothian
 * 10 September 1912
 * Alexander Murray
 * John Hope
 * Succession
 * East Carmarthenshire
 * 22 August 1912
 * Abel Thomas
 * Rev Josiah Towyn Jones
 * Death
 * - bgcolor=lightblue
 * Manchester North West
 * 8 August 1912
 * Sir George Kemp
 * Sir John Randles
 * Resignation
 * -bgcolor=lightblue
 * Crewe
 * 26 July 1912
 * Walter McLaren
 * Ernest Craig
 * Death
 * - bgcolor=FFCC66
 * Hanley
 * 13 July 1912
 * Enoch Edwards
 * R. L. Outhwaite
 * Death
 * Ilkeston
 * 1 July 1912
 * J. E. B. Seely
 * J. E. B. Seely
 * Secretary of State for War
 * Holmfirth
 * 20 June 1912
 * Henry Wilson
 * Sydney Arnold
 * Resignation
 * Hythe
 * 11 June 1912
 * Sir Edward Sassoon
 * Sir Philip Sassoon
 * Death
 * North West Norfolk
 * 31 May 1912
 * Sir George White
 * Edward Hemmerde
 * Death
 * - bgcolor=FFCC66
 * Hackney South
 * 24 May 1912
 * Horatio Bottomley
 * Hector Morison
 * Resignation
 * Forest of Dean
 * 30 April 1912
 * Henry Webb
 * Henry Webb
 * Commissioner of the Treasury
 * Nottingham East
 * 19 April 1912
 * James Morrison
 * Sir John David Rees
 * Resignation
 * Epsom
 * 21 March 1912
 * William Keswick
 * Henry Keswick
 * Death
 * Leominster
 * 18 March 1912
 * Sir James Rankin
 * Henry FitzHerbert Wright
 * Resignation
 * South East Essex
 * 16 March 1912
 * John Kirkwood
 * Hon. Rupert Guinness
 * Resignation
 * Hereford
 * 8 March 1912
 * John Arkwright
 * William Hewins
 * Resignation
 * - bgcolor=lightblue
 * Manchester South
 * 5 March 1912
 * Sir Arthur Haworth
 * Philip Glazebrook
 * Commissioner of the Treasury
 * Glasgow St Rollox
 * 26 February 1912
 * Thomas McKinnon Wood
 * Thomas McKinnon Wood
 * Secretary for Scotland
 * Edinburgh East
 * 2 February 1912
 * Sir James Gibson
 * James Hogge
 * Death
 * Carmarthen District
 * 29 January 1912
 * W. Llewelyn Williams
 * W. Llewelyn Williams
 * Recorder of Swansea
 * Govan
 * 22 December 1911
 * William Hunter
 * Daniel Holmes
 * Senator of the College of Justice
 * - bgcolor=lightblue
 * North Ayrshire
 * 20 December 1911
 * Andrew Anderson
 * Duncan Campbell
 * Solicitor General for Scotland
 * Hitchin
 * 23 November 1911
 * Dr Alfred Hillier
 * Robert Cecil
 * Death
 * - bgcolor=lightblue
 * South Somerset
 * 21 November 1911
 * Sir Edward Strachey
 * Aubrey Herbert
 * Elevation
 * - bgcolor=lightblue
 * Oldham
 * 13 November 1911
 * Alfred Emmott
 * Edmund Denniss
 * Elevation
 * Bristol East
 * 3 November 1911
 * Charles Hobhouse
 * Charles Hobhouse
 * Chancellor of the Duchy of Lancaster
 * Keighley
 * 27 October 1911
 * Sir John Brigg
 * Stanley Buckmaster
 * Death
 * North Tyrone
 * 6 October 1911
 * Redmond Barry
 * Thomas Russell
 * Lord Chancellor of Ireland
 * Kilmarnock Burghs
 * 26 September 1911
 * Adam Rainy
 * William Glynne Charles Gladstone
 * Death
 * Middleton
 * 2 August 1911
 * Sir William Adkins
 * Sir William Adkins
 * Recorder of Nottingham
 * Bethnal Green South West
 * 29 July 1911
 * Edward Pickersgill
 * Charles Masterman
 * Resignation
 * Wellington
 * 21 July 1911
 * Sir Alexander Acland Hood
 * Dennis Boles
 * Elevation
 * Luton
 * 20 July 1911
 * Thomas Ashton
 * Cecil Harmsworth
 * Elevation
 * East Cork
 * 15 July 1911
 * Anthony Donelan
 * John Muldoon
 * Election declared void
 * North East Cork
 * 15 July 1911
 * Moreton Frewen
 * Tim Healy
 * Resignation
 * East Wicklow
 * 13 July 1911
 * John Muldoon
 * Anthony Donelan
 * Resignation in order to contest East Cork
 * West Ham North
 * 8 July 1911
 * Charles Masterman
 * Baron Maurice de Forest
 * Election declared void
 * St Augustine's
 * 7 July 1911
 * Aretas Akers-Douglas
 * Ronald McNeill
 * Elevation
 * Glasgow Tradeston
 * 6 July 1911
 * Archibald Corbett
 * J. D. White
 * Elevation
 * Kingston upon Hull Central
 * 5 July 1911
 * Sir Henry King
 * Mark Sykes
 * Election declared void
 * Brighton
 * 26 June 1911
 * Hon Walter Rice
 * Hon John Gordon
 * Succession
 * Ross and Cromarty
 * 14 June 1911
 * James Galloway Weir
 * Ian Macpherson
 * Death
 * Barnstaple
 * 6 May 1911
 * Ernest Soares
 * Sir Godfrey Baring
 * Appointed to the National Debt Office
 * Birmingham South
 * 3 May 1911
 * Charles Howard
 * Leo Amery
 * Succession
 * East Dorset
 * 29 April 1911
 * Hon Frederick Guest
 * Hon Frederick Guest
 * Commissioner of the Treasury
 * - bgcolor=lightblue
 * Cheltenham
 * 28 April 1911
 * Richard Mathias
 * James Agg-Gardner
 * Election declared void
 * Haddingtonshire
 * 19 April 1911
 * Sir Richard Haldane
 * John Deans Hope
 * Hereditary Peerage on appointment as Lord High Chancellor of Great Britain
 * Bootle
 * 27 March 1911
 * Thomas Sandys
 * Bonar Law
 * Resignation
 * Brentford
 * 23 March 1911
 * Lord Alwyne Compton
 * William Joynson-Hicks
 * Resignation
 * North Louth
 * 15 March 1911
 * Richard Hazleton
 * Augustine Roche
 * Void Election
 * North East Lanarkshire
 * 9 March 1911
 * Thomas Fleming Wilson
 * James Duncan Millar
 * Resignation
 * Forest of Dean
 * 24 February 1911
 * Sir Charles Dilke
 * Henry Webb
 * Death
 * Westbury
 * 22 February 1911
 * Sir John Fuller
 * Hon Geoffrey Howard
 * Resignation
 * Horncastle
 * 16 February 1911
 * Lord Willoughby de Eresby
 * William Weigall
 * Succession
 * Cambridge University
 * 11–16 February 1911
 * Samuel Butcher
 * Sir Joseph Larmor
 * Death
 * Arfon
 * 11 February 1911
 * William Jones
 * William Jones
 * Commissioner of the Treasury
 * colspan=9|
 * Hitchin
 * 23 November 1911
 * Dr Alfred Hillier
 * Robert Cecil
 * Death
 * - bgcolor=lightblue
 * South Somerset
 * 21 November 1911
 * Sir Edward Strachey
 * Aubrey Herbert
 * Elevation
 * - bgcolor=lightblue
 * Oldham
 * 13 November 1911
 * Alfred Emmott
 * Edmund Denniss
 * Elevation
 * Bristol East
 * 3 November 1911
 * Charles Hobhouse
 * Charles Hobhouse
 * Chancellor of the Duchy of Lancaster
 * Keighley
 * 27 October 1911
 * Sir John Brigg
 * Stanley Buckmaster
 * Death
 * North Tyrone
 * 6 October 1911
 * Redmond Barry
 * Thomas Russell
 * Lord Chancellor of Ireland
 * Kilmarnock Burghs
 * 26 September 1911
 * Adam Rainy
 * William Glynne Charles Gladstone
 * Death
 * Middleton
 * 2 August 1911
 * Sir William Adkins
 * Sir William Adkins
 * Recorder of Nottingham
 * Bethnal Green South West
 * 29 July 1911
 * Edward Pickersgill
 * Charles Masterman
 * Resignation
 * Wellington
 * 21 July 1911
 * Sir Alexander Acland Hood
 * Dennis Boles
 * Elevation
 * Luton
 * 20 July 1911
 * Thomas Ashton
 * Cecil Harmsworth
 * Elevation
 * East Cork
 * 15 July 1911
 * Anthony Donelan
 * John Muldoon
 * Election declared void
 * North East Cork
 * 15 July 1911
 * Moreton Frewen
 * Tim Healy
 * Resignation
 * East Wicklow
 * 13 July 1911
 * John Muldoon
 * Anthony Donelan
 * Resignation in order to contest East Cork
 * West Ham North
 * 8 July 1911
 * Charles Masterman
 * Baron Maurice de Forest
 * Election declared void
 * St Augustine's
 * 7 July 1911
 * Aretas Akers-Douglas
 * Ronald McNeill
 * Elevation
 * Glasgow Tradeston
 * 6 July 1911
 * Archibald Corbett
 * J. D. White
 * Elevation
 * Kingston upon Hull Central
 * 5 July 1911
 * Sir Henry King
 * Mark Sykes
 * Election declared void
 * Brighton
 * 26 June 1911
 * Hon Walter Rice
 * Hon John Gordon
 * Succession
 * Ross and Cromarty
 * 14 June 1911
 * James Galloway Weir
 * Ian Macpherson
 * Death
 * Barnstaple
 * 6 May 1911
 * Ernest Soares
 * Sir Godfrey Baring
 * Appointed to the National Debt Office
 * Birmingham South
 * 3 May 1911
 * Charles Howard
 * Leo Amery
 * Succession
 * East Dorset
 * 29 April 1911
 * Hon Frederick Guest
 * Hon Frederick Guest
 * Commissioner of the Treasury
 * - bgcolor=lightblue
 * Cheltenham
 * 28 April 1911
 * Richard Mathias
 * James Agg-Gardner
 * Election declared void
 * Haddingtonshire
 * 19 April 1911
 * Sir Richard Haldane
 * John Deans Hope
 * Hereditary Peerage on appointment as Lord High Chancellor of Great Britain
 * Bootle
 * 27 March 1911
 * Thomas Sandys
 * Bonar Law
 * Resignation
 * Brentford
 * 23 March 1911
 * Lord Alwyne Compton
 * William Joynson-Hicks
 * Resignation
 * North Louth
 * 15 March 1911
 * Richard Hazleton
 * Augustine Roche
 * Void Election
 * North East Lanarkshire
 * 9 March 1911
 * Thomas Fleming Wilson
 * James Duncan Millar
 * Resignation
 * Forest of Dean
 * 24 February 1911
 * Sir Charles Dilke
 * Henry Webb
 * Death
 * Westbury
 * 22 February 1911
 * Sir John Fuller
 * Hon Geoffrey Howard
 * Resignation
 * Horncastle
 * 16 February 1911
 * Lord Willoughby de Eresby
 * William Weigall
 * Succession
 * Cambridge University
 * 11–16 February 1911
 * Samuel Butcher
 * Sir Joseph Larmor
 * Death
 * Arfon
 * 11 February 1911
 * William Jones
 * William Jones
 * Commissioner of the Treasury
 * colspan=9|
 * Succession
 * East Dorset
 * 29 April 1911
 * Hon Frederick Guest
 * Hon Frederick Guest
 * Commissioner of the Treasury
 * - bgcolor=lightblue
 * Cheltenham
 * 28 April 1911
 * Richard Mathias
 * James Agg-Gardner
 * Election declared void
 * Haddingtonshire
 * 19 April 1911
 * Sir Richard Haldane
 * John Deans Hope
 * Hereditary Peerage on appointment as Lord High Chancellor of Great Britain
 * Bootle
 * 27 March 1911
 * Thomas Sandys
 * Bonar Law
 * Resignation
 * Brentford
 * 23 March 1911
 * Lord Alwyne Compton
 * William Joynson-Hicks
 * Resignation
 * North Louth
 * 15 March 1911
 * Richard Hazleton
 * Augustine Roche
 * Void Election
 * North East Lanarkshire
 * 9 March 1911
 * Thomas Fleming Wilson
 * James Duncan Millar
 * Resignation
 * Forest of Dean
 * 24 February 1911
 * Sir Charles Dilke
 * Henry Webb
 * Death
 * Westbury
 * 22 February 1911
 * Sir John Fuller
 * Hon Geoffrey Howard
 * Resignation
 * Horncastle
 * 16 February 1911
 * Lord Willoughby de Eresby
 * William Weigall
 * Succession
 * Cambridge University
 * 11–16 February 1911
 * Samuel Butcher
 * Sir Joseph Larmor
 * Death
 * Arfon
 * 11 February 1911
 * William Jones
 * William Jones
 * Commissioner of the Treasury
 * colspan=9|
 * Henry Webb
 * Death
 * Westbury
 * 22 February 1911
 * Sir John Fuller
 * Hon Geoffrey Howard
 * Resignation
 * Horncastle
 * 16 February 1911
 * Lord Willoughby de Eresby
 * William Weigall
 * Succession
 * Cambridge University
 * 11–16 February 1911
 * Samuel Butcher
 * Sir Joseph Larmor
 * Death
 * Arfon
 * 11 February 1911
 * William Jones
 * William Jones
 * Commissioner of the Treasury
 * colspan=9|
 * Sir Joseph Larmor
 * Death
 * Arfon
 * 11 February 1911
 * William Jones
 * William Jones
 * Commissioner of the Treasury
 * colspan=9|
 * William Jones
 * Commissioner of the Treasury
 * colspan=9|
 * Commissioner of the Treasury
 * colspan=9|
 * colspan=9|

29th Parliament (January 1910 – December 1910)
!By-election !! Date !! Incumbent !! colspan=2 | Party !! Winner !! colspan=2 | Party !! Cause
 * Walthamstow
 * 1 November 1910
 * John Simon
 * Sir John Simon
 * Solicitor General for England and Wales
 * South Shields
 * 27 October 1910
 * Sir William Robson
 * Russell Rea
 * Lord of Appeal
 * Liverpool Kirkdale
 * 20 July 1910
 * Charles McArthur
 * Gerald Kyffin-Taylor
 * Death
 * East Dorset
 * 30 June 1910
 * Frederick Guest
 * Henry Guest
 * Election declared void
 * Hartlepool
 * 20 June 1910
 * Sir Christopher Furness
 * Stephen Furness
 * Election declared void
 * Lewes
 * 17 June 1910
 * Sir Henry Aubrey-Fletcher
 * William Campion
 * Death
 * Dublin Harbour
 * 14 June 1910
 * Timothy Harrington
 * William Abraham
 * Death
 * Crewe
 * 30 April 1910
 * James Tomkinson
 * Walter McLaren
 * Death
 * Edinburgh South
 * 29 April 1910
 * Arthur Dewar
 * Charles Henry Lyell
 * Senator of the College of Justice
 * North Down
 * 28 April 1910
 * Thomas Corbett
 * William Mitchell-Thomson
 * Death
 * Govan
 * 28 April 1910
 * William Hunter
 * William Hunter
 * Solicitor General for Scotland
 * Mid Glamorganshire
 * 31 March 1910
 * Sir Samuel Thomas Evans
 * Frederick Gibbins
 * President of the Probate and Divorce Division of the High Court of Justice
 * West Wicklow
 * 29 March 1910
 * James O'Connor
 * Edward Peter O'Kelly
 * Death
 * Reading
 * 12 March 1910
 * Rufus Isaacs
 * Rufus Isaacs
 * Solicitor General for England and Wales
 * Shipley
 * 10 March 1910
 * Percy Illingworth
 * Percy Illingworth
 * Commissioner of the Treasury
 * Ilkeston
 * 7 March 1910
 * Balthazar Foster
 * J. E. B. Seely
 * Resignation
 * North East Cork
 * 2 March 1910
 * William O'Brien
 * Maurice Healy
 * Elected to sit for Cork City
 * Barnstaple
 * 2 March 1910
 * Ernest Soares
 * Ernest Soares
 * Commissioner of the Treasury
 * Rotherham
 * 1 March 1910
 * Sir William Holland
 * Jack Pease
 * Resignation
 * Tower Hamlets St George
 * 1 March 1910
 * William Wedgwood Benn
 * William Wedgwood Benn
 * Commissioner of the Treasury
 * Swansea District
 * 28 February 1910
 * Sir David Brynmor Jones
 * Sir David Brynmor Jones
 * Recorder of Merthyr Tydvil
 * colspan=9|
 * 12 March 1910
 * Rufus Isaacs
 * Rufus Isaacs
 * Solicitor General for England and Wales
 * Shipley
 * 10 March 1910
 * Percy Illingworth
 * Percy Illingworth
 * Commissioner of the Treasury
 * Ilkeston
 * 7 March 1910
 * Balthazar Foster
 * J. E. B. Seely
 * Resignation
 * North East Cork
 * 2 March 1910
 * William O'Brien
 * Maurice Healy
 * Elected to sit for Cork City
 * Barnstaple
 * 2 March 1910
 * Ernest Soares
 * Ernest Soares
 * Commissioner of the Treasury
 * Rotherham
 * 1 March 1910
 * Sir William Holland
 * Jack Pease
 * Resignation
 * Tower Hamlets St George
 * 1 March 1910
 * William Wedgwood Benn
 * William Wedgwood Benn
 * Commissioner of the Treasury
 * Swansea District
 * 28 February 1910
 * Sir David Brynmor Jones
 * Sir David Brynmor Jones
 * Recorder of Merthyr Tydvil
 * colspan=9|
 * 1 March 1910
 * Sir William Holland
 * Jack Pease
 * Resignation
 * Tower Hamlets St George
 * 1 March 1910
 * William Wedgwood Benn
 * William Wedgwood Benn
 * Commissioner of the Treasury
 * Swansea District
 * 28 February 1910
 * Sir David Brynmor Jones
 * Sir David Brynmor Jones
 * Recorder of Merthyr Tydvil
 * colspan=9|
 * Swansea District
 * 28 February 1910
 * Sir David Brynmor Jones
 * Sir David Brynmor Jones
 * Recorder of Merthyr Tydvil
 * colspan=9|
 * Recorder of Merthyr Tydvil
 * colspan=9|
 * colspan=9|

28th Parliament (1906 – January 1910)
!By-election !! Date !! Incumbent !! colspan=2 | Party !! Winner !! colspan=2 | Party !! Cause
 * South Armagh
 * 5 November 1909
 * William McKillop
 * Charles O'Neill
 * Death
 * - bgcolor=lightblue
 * Bermondsey
 * 28 October 1909
 * George Cooper
 * John Dumphreys
 * Death
 * West Clare
 * 3 September 1909
 * James Halpin
 * Arthur Lynch
 * Death
 * South Kilkenny
 * 10 August 1909
 * Nicholas Joseph Murphy
 * Matthew Keating
 * Declared bankrupt
 * North Sligo
 * 5 August 1909
 * P. A. McHugh
 * Thomas Scanlan
 * Death
 * High Peak
 * 22 July 1909
 * Oswald Partington
 * Oswald Partington
 * Appointed Junior Lord of the Treasury
 * Dumfries Burghs
 * 20 July 1909
 * John Gulland
 * John Gulland
 * Appointed Junior Lord of the Treasury
 * Mid Derbyshire
 * 15 July 1909
 * James Alfred Jacoby
 * John Hancock
 * Death
 * Cleveland
 * 9 July 1909
 * Herbert Samuel
 * Herbert Samuel
 * Appointed Chancellor of the Duchy of Lancaster
 * East Limerick
 * 10 June 1909
 * William Lundon
 * Thomas Lundon
 * Death
 * Edinburgh West
 * 17 May 1909
 * Lewis McIver
 * James Avon Clyde
 * Resignation
 * - bgcolor=lightblue
 * Stratford-on-Avon
 * 4 May 1909
 * Thomas Kincaid-Smith
 * Philip Staveley Foster
 * Resigned to restand following his resignation from the Liberal Party
 * - bgcolor=pink
 * Sheffield Attercliffe
 * 4 May 1909
 * J. Batty Langley
 * Joseph Pointer
 * Resignation
 * - bgcolor=#c0c0c0
 * Cork City
 * 1 May 1909
 * William O'Brien
 * Maurice Healy
 * Resignation
 * Edinburgh East
 * 16 April 1909
 * George McCrae
 * James Gibson
 * Resignation
 * East Denbighshire
 * 2 April 1909
 * Edward Hemmerde
 * Edward Hemmerde
 * Recorder of Liverpool
 * Croydon
 * 29 March 1909
 * H. O. Arnold-Forster
 * Robert Hermon-Hodge
 * Death
 * Hawick Burghs
 * 5 March 1909
 * Thomas Shaw
 * John Barran
 * Resignation (appointed Lord of Appeal in Ordinary)
 * Edinburgh South
 * 4 March 1909
 * Arthur Dewar
 * Arthur Dewar
 * Appointed Solicitor General for Scotland
 * - bgcolor=lightblue
 * Glasgow Central
 * 2 March 1909
 * Andrew Mitchell Torrance
 * Charles Dickson
 * Death
 * Forfarshire
 * 27 February 1909
 * John Sinclair
 * James Falconer
 * Elevation to the peerage
 * Taunton
 * 23 February 1909
 * Edward Boyle
 * William Peel
 * Resignation
 * Tamworth
 * 16 January 1909
 * Sir Philip Muntz
 * Francis Newdegate
 * Death
 * Chelmsford
 * 1 December 1908
 * Carne Rasch
 * E. G. Pretyman
 * Resignation
 * - bgcolor=lightblue
 * Newcastle-upon-Tyne
 * 25 September 1908
 * Thomas Cairns
 * George Renwick
 * Death
 * - bgcolor=lightblue
 * Haggerston
 * 1 August 1908
 * Randal Cremer
 * Rupert Guinness
 * Death
 * Pembrokeshire
 * 16 July 1908
 * John Philipps
 * Walter Roch
 * Elevation to the peerage
 * - bgcolor=lightblue
 * Pudsey
 * 20 June 1908
 * George Whiteley
 * John James Oddy
 * Resignation
 * Stirling Burghs
 * 22 May 1908
 * Henry Campbell-Bannerman
 * Arthur Ponsonby
 * Death
 * Newport (Shropshire)
 * 14 May 1908
 * William Kenyon-Slaney
 * Beville Stanier
 * Death
 * Montrose Burghs
 * 12 May 1908
 * John Morley
 * Robert Harcourt
 * Elevation to the peerage
 * Dundee
 * 9 May 1908
 * Edmund Robertson
 * Winston Churchill
 * Elevation to the peerage
 * Wolverhampton East
 * 5 May 1908
 * Henry Fowler
 * George Rennie Thorne
 * Elevation to the peerage
 * Kincardineshire
 * 25 April 1908
 * John William Crombie
 * Arthur Murray
 * Death
 * - bgcolor=lightblue
 * Manchester North West
 * 24 April 1908
 * Winston Churchill
 * William Joynson-Hicks
 * Appointed President of the Board of Trade
 * Dewsbury
 * 23 April 1908
 * Walter Runciman
 * Walter Runciman
 * Appointed President of the Board of Education
 * Sheffield Central
 * 21 April 1908
 * Howard Vincent
 * James Hope
 * Death
 * West Derbyshire
 * 15 April 1908
 * Victor Cavendish
 * Henry Petty-Fitzmaurice
 * Succession to the peerage
 * - bgcolor=lightblue
 * Peckham
 * 24 March 1908
 * Charles Clarke
 * Harry Gooch
 * Death
 * West Down
 * 20 March 1908
 * Arthur Hill
 * William MacCaw
 * Resignation
 * Hastings
 * 3 March 1908
 * Harvey du Cros
 * Arthur du Cros
 * Resignation
 * Bewdley
 * 29 February 1908
 * Alfred Baldwin
 * Stanley Baldwin
 * Death
 * West Carmarthenshire
 * 26 February 1908
 * John Lloyd Morgan
 * John Lloyd Morgan
 * Recorder of Swansea
 * North Leitrim
 * 21 February 1908
 * Charles Dolan
 * Francis Meehan
 * Resignation
 * Leeds South
 * 13 February 1908
 * John Lawson Walton
 * William Middlebrook
 * Death
 * Mid Glamorganshire
 * 7 February 1908
 * Samuel Thomas Evans
 * Samuel Thomas Evans
 * Solicitor-General for England and Wales
 * Worcester
 * 7 February 1908
 * George Henry Williamson
 * Edward Goulding
 * Void election
 * St Austell
 * 5 February 1908
 * William Alexander McArthur
 * Thomas Agar-Robartes
 * Resignation
 * County Carlow
 * 3 February 1908
 * John Hammond
 * Walter Kavanagh
 * Death
 * - bgcolor=lightblue
 * Ross
 * 31 January 1908
 * Alan Coulstoun Gardner
 * Percy Clive
 * Death
 * - bgcolor=lightblue
 * Ashburton
 * 17 January 1908
 * Harry Trelawney Eve
 * Ernest Morrison-Bell
 * Appointment as a judge
 * Kingston upon Hull West
 * 29 November 1907
 * Charles Wilson
 * Guy Greville Wilson
 * Succession to peerage
 * Liverpool Kirkdale
 * 27 September 1907
 * David MacIver
 * Charles McArthur
 * Death
 * South Longford
 * 6 September 1907
 * Edward Blake
 * John Phillips
 * Resignation
 * West Down
 * 6 September 1907
 * Harry Liddell
 * Arthur Hill
 * Resignation
 * Bury St Edmunds
 * 24 August 1907
 * Frederick Hervey
 * Walter Guinness
 * Succession to the peerage
 * Anglesey
 * 21 August 1907
 * Ellis Griffith
 * Ellis Griffith
 * Recorder of Birkenhead
 * North West Staffordshire
 * 31 July 1907
 * Alfred Billson
 * Albert Stanley
 * Death
 * East Wicklow
 * 29 July 1907
 * Denis Joseph Cogan
 * John Muldoon
 * Resignation
 * South Kilkenny
 * 29 July 1907
 * James O'Mara
 * Nicholas Joseph Murphy
 * Resignation
 * - bgcolor=#c0c0c0
 * Colne Valley
 * 18 July 1907
 * James Kitson
 * Victor Grayson
 * Elevation to the peerage
 * - bgcolor=pink
 * Jarrow
 * 4 July 1907
 * Charles Palmer
 * Pete Curran
 * Death
 * North Monaghan
 * 20 June 1907
 * Patrick O'Hare
 * James Carrige Rushe Lardner
 * Resignation
 * Rutlandshire
 * 11 June 1907
 * George Finch
 * John Gretton
 * Death
 * Hornsey
 * 5 June 1907
 * Charles Balfour
 * Lawrence Dundas
 * Resignation
 * Wimbledon
 * 14 May 1907
 * Eric Hambro
 * Henry Chaplin
 * Resignation
 * Stepney
 * 10 May 1907
 * William Evans-Gordon
 * Frederick Leverton Harris
 * Resignation
 * North Belfast
 * 17 April 1907
 * Daniel Dixon
 * George Clark
 * Death
 * South Westmeath
 * 13 April 1907
 * Donal Sullivan
 * Walter Nugent
 * Death
 * Hexham
 * 27 March 1907
 * Wentworth Beaumont
 * Richard Durning Holt
 * Succession to the peerage
 * North Tyrone
 * 8 March 1907
 * William Huston Dodd
 * Redmond Barry
 * Appointed as a Judge
 * Halifax
 * 6 March 1907
 * John Henry Whitley
 * John Henry Whitley
 * Appointed Junior Lord of the Treasury
 * - bgcolor=lightblue
 * Brigg
 * 26 February 1907
 * Harold Reckitt
 * Berkeley Sheffield
 * Resignation
 * Aberdeen South
 * 20 February 1907
 * James Bryce
 * George Esslemont
 * Appointed British Ambassador to the United States
 * North Monmouthshire
 * 19 February 1907
 * Reginald McKenna
 * Reginald McKenna
 * Appointed President of the Board of Education
 * Banffshire
 * 16 February 1907
 * Alexander William Black
 * Walter Waring
 * Death
 * Perth
 * 12 February 1907
 * Robert Wallace
 * Robert Pullar
 * Resignation
 * North East Derbyshire
 * 30 January 1907
 * Thomas Bolton
 * W. E. Harvey
 * Death
 * - bgcolor=#c0c0c0
 * Mid Cork
 * 31 December 1906
 * D. D. Sheehan
 * D. D. Sheehan
 * Resigned following expulsion from Nationalist group
 * Huddersfield
 * 28 November 1906
 * James Woodhouse
 * Arthur Sherwell
 * Appointed Rail and Canal Traffic Commissioner
 * North Armagh
 * 16 November 1906
 * Edward James Saunderson
 * William Moore
 * Death
 * Galway Borough
 * 3 November 1906
 * Charles Ramsay Devlin
 * Stephen Gwynn
 * Resignation
 * Mid Glamorganshire
 * 8 October 1906
 * Samuel Thomas Evans
 * Samuel Thomas Evans
 * Recorder of Swansea
 * East Denbighshire
 * 14 August 1906
 * Samuel Moss
 * Edward Hemmerde
 * Resignation
 * - bgcolor=lightblue
 * Cockermouth
 * 3 August 1906
 * Sir Wilfrid Lawson
 * Sir John Scurrah Randles
 * Death
 * East Tyrone
 * 5 July 1906
 * Patrick Doogan
 * Thomas Kettle
 * Death
 * Bodmin
 * 24 July 1906
 * Hon Thomas Agar-Robartes
 * Freeman Freeman-Thomas
 * Unseated on petition
 * St George's, Hanover Square
 * 15 June 1906
 * Heneage Legge
 * Alfred Lyttelton
 * Resignation
 * City of London
 * 15 June 1906
 * Sir Edward Clarke
 * Frederick Banbury
 * Resignation
 * Eifion
 * 5 June 1906
 * John Bryn Roberts
 * Ellis William Davies
 * Resignation
 * Dulwich
 * 15 May 1906
 * Frederick Rutherfoord Harris
 * Bonar Law
 * Went abroad
 * Eye
 * 6 April 1906
 * Francis Seymour Stevenson
 * Harold Pearson
 * Resignation
 * Leicester
 * 30 March 1906
 * Henry Broadhurst
 * Franklin Thomasson
 * Resignation
 * Basingstoke
 * 12 March 1906
 * Arthur Frederick Jeffreys
 * Arthur Salter
 * Death
 * North Kilkenny
 * 3 March 1906
 * Joseph Devlin
 * Michael Meagher
 * Double election, chose to sit for Belfast West
 * North Leitrim
 * 28 February 1906
 * P. A. McHugh
 * Charles Dolan
 * Double election, chose to sit for North Sligo
 * North Galway
 * 28 February 1906
 * Thomas Higgins
 * Richard Hazleton
 * Death
 * East Aberdeenshire
 * 28 February 1906
 * James Annand
 * James Murray
 * Death
 * City of London
 * 27 February 1906
 * Alban Gibbs
 * Arthur Balfour
 * Retired in favour of Balfour
 * Westbury
 * 26 February 1906
 * John Fuller
 * John Fuller
 * Appointed a Lord Commissioner of the Treasury
 * colspan=9 |
 * Resignation
 * Wimbledon
 * 14 May 1907
 * Eric Hambro
 * Henry Chaplin
 * Resignation
 * Stepney
 * 10 May 1907
 * William Evans-Gordon
 * Frederick Leverton Harris
 * Resignation
 * North Belfast
 * 17 April 1907
 * Daniel Dixon
 * George Clark
 * Death
 * South Westmeath
 * 13 April 1907
 * Donal Sullivan
 * Walter Nugent
 * Death
 * Hexham
 * 27 March 1907
 * Wentworth Beaumont
 * Richard Durning Holt
 * Succession to the peerage
 * North Tyrone
 * 8 March 1907
 * William Huston Dodd
 * Redmond Barry
 * Appointed as a Judge
 * Halifax
 * 6 March 1907
 * John Henry Whitley
 * John Henry Whitley
 * Appointed Junior Lord of the Treasury
 * - bgcolor=lightblue
 * Brigg
 * 26 February 1907
 * Harold Reckitt
 * Berkeley Sheffield
 * Resignation
 * Aberdeen South
 * 20 February 1907
 * James Bryce
 * George Esslemont
 * Appointed British Ambassador to the United States
 * North Monmouthshire
 * 19 February 1907
 * Reginald McKenna
 * Reginald McKenna
 * Appointed President of the Board of Education
 * Banffshire
 * 16 February 1907
 * Alexander William Black
 * Walter Waring
 * Death
 * Perth
 * 12 February 1907
 * Robert Wallace
 * Robert Pullar
 * Resignation
 * North East Derbyshire
 * 30 January 1907
 * Thomas Bolton
 * W. E. Harvey
 * Death
 * - bgcolor=#c0c0c0
 * Mid Cork
 * 31 December 1906
 * D. D. Sheehan
 * D. D. Sheehan
 * Resigned following expulsion from Nationalist group
 * Huddersfield
 * 28 November 1906
 * James Woodhouse
 * Arthur Sherwell
 * Appointed Rail and Canal Traffic Commissioner
 * North Armagh
 * 16 November 1906
 * Edward James Saunderson
 * William Moore
 * Death
 * Galway Borough
 * 3 November 1906
 * Charles Ramsay Devlin
 * Stephen Gwynn
 * Resignation
 * Mid Glamorganshire
 * 8 October 1906
 * Samuel Thomas Evans
 * Samuel Thomas Evans
 * Recorder of Swansea
 * East Denbighshire
 * 14 August 1906
 * Samuel Moss
 * Edward Hemmerde
 * Resignation
 * - bgcolor=lightblue
 * Cockermouth
 * 3 August 1906
 * Sir Wilfrid Lawson
 * Sir John Scurrah Randles
 * Death
 * East Tyrone
 * 5 July 1906
 * Patrick Doogan
 * Thomas Kettle
 * Death
 * Bodmin
 * 24 July 1906
 * Hon Thomas Agar-Robartes
 * Freeman Freeman-Thomas
 * Unseated on petition
 * St George's, Hanover Square
 * 15 June 1906
 * Heneage Legge
 * Alfred Lyttelton
 * Resignation
 * City of London
 * 15 June 1906
 * Sir Edward Clarke
 * Frederick Banbury
 * Resignation
 * Eifion
 * 5 June 1906
 * John Bryn Roberts
 * Ellis William Davies
 * Resignation
 * Dulwich
 * 15 May 1906
 * Frederick Rutherfoord Harris
 * Bonar Law
 * Went abroad
 * Eye
 * 6 April 1906
 * Francis Seymour Stevenson
 * Harold Pearson
 * Resignation
 * Leicester
 * 30 March 1906
 * Henry Broadhurst
 * Franklin Thomasson
 * Resignation
 * Basingstoke
 * 12 March 1906
 * Arthur Frederick Jeffreys
 * Arthur Salter
 * Death
 * North Kilkenny
 * 3 March 1906
 * Joseph Devlin
 * Michael Meagher
 * Double election, chose to sit for Belfast West
 * North Leitrim
 * 28 February 1906
 * P. A. McHugh
 * Charles Dolan
 * Double election, chose to sit for North Sligo
 * North Galway
 * 28 February 1906
 * Thomas Higgins
 * Richard Hazleton
 * Death
 * East Aberdeenshire
 * 28 February 1906
 * James Annand
 * James Murray
 * Death
 * City of London
 * 27 February 1906
 * Alban Gibbs
 * Arthur Balfour
 * Retired in favour of Balfour
 * Westbury
 * 26 February 1906
 * John Fuller
 * John Fuller
 * Appointed a Lord Commissioner of the Treasury
 * colspan=9 |
 * 15 June 1906
 * Heneage Legge
 * Alfred Lyttelton
 * Resignation
 * City of London
 * 15 June 1906
 * Sir Edward Clarke
 * Frederick Banbury
 * Resignation
 * Eifion
 * 5 June 1906
 * John Bryn Roberts
 * Ellis William Davies
 * Resignation
 * Dulwich
 * 15 May 1906
 * Frederick Rutherfoord Harris
 * Bonar Law
 * Went abroad
 * Eye
 * 6 April 1906
 * Francis Seymour Stevenson
 * Harold Pearson
 * Resignation
 * Leicester
 * 30 March 1906
 * Henry Broadhurst
 * Franklin Thomasson
 * Resignation
 * Basingstoke
 * 12 March 1906
 * Arthur Frederick Jeffreys
 * Arthur Salter
 * Death
 * North Kilkenny
 * 3 March 1906
 * Joseph Devlin
 * Michael Meagher
 * Double election, chose to sit for Belfast West
 * North Leitrim
 * 28 February 1906
 * P. A. McHugh
 * Charles Dolan
 * Double election, chose to sit for North Sligo
 * North Galway
 * 28 February 1906
 * Thomas Higgins
 * Richard Hazleton
 * Death
 * East Aberdeenshire
 * 28 February 1906
 * James Annand
 * James Murray
 * Death
 * City of London
 * 27 February 1906
 * Alban Gibbs
 * Arthur Balfour
 * Retired in favour of Balfour
 * Westbury
 * 26 February 1906
 * John Fuller
 * John Fuller
 * Appointed a Lord Commissioner of the Treasury
 * colspan=9 |
 * P. A. McHugh
 * Charles Dolan
 * Double election, chose to sit for North Sligo
 * North Galway
 * 28 February 1906
 * Thomas Higgins
 * Richard Hazleton
 * Death
 * East Aberdeenshire
 * 28 February 1906
 * James Annand
 * James Murray
 * Death
 * City of London
 * 27 February 1906
 * Alban Gibbs
 * Arthur Balfour
 * Retired in favour of Balfour
 * Westbury
 * 26 February 1906
 * John Fuller
 * John Fuller
 * Appointed a Lord Commissioner of the Treasury
 * colspan=9 |
 * Alban Gibbs
 * Arthur Balfour
 * Retired in favour of Balfour
 * Westbury
 * 26 February 1906
 * John Fuller
 * John Fuller
 * Appointed a Lord Commissioner of the Treasury
 * colspan=9 |
 * John Fuller
 * Appointed a Lord Commissioner of the Treasury
 * colspan=9 |
 * Appointed a Lord Commissioner of the Treasury
 * colspan=9 |
 * colspan=9 |

27th Parliament (1900–1906)
!By-election !! Date !! Incumbent !! colspan=2 | Party !! Winner !! colspan=2 | Party !! Cause
 * New Forest
 * 6 December 1905
 * John Douglas-Scott-Montagu
 * Henry Francis Compton
 * Succession to peerage
 * Normanton
 * 27 November 1905
 * William Parrott
 * Frederick Hall
 * Death
 * Hampstead
 * 26 October 1905
 * Thomas Milvain
 * John Fletcher
 * Judge Advocate General
 * - bgcolor=FFCC66
 * Barkston Ash
 * 13 October 1905
 * Sir Robert Gunter
 * Joseph Andrews
 * Death
 * Belfast North
 * 14 September 1905
 * Sir James Horner Haslett
 * Sir Daniel Dixon
 * Death
 * Elgin Burghs
 * 8 September 1905
 * Alexander Asher
 * John Sutherland
 * Death
 * Carlisle
 * 14 July 1905
 * William Gully
 * Frederick Chance
 * Elevation to the peerage
 * West Down
 * 10 July 1905
 * Arthur Hill
 * Harry Liddell
 * Resignation
 * Kingswinford
 * 3 July 1905
 * William George Webb
 * Henry Staveley-Hill
 * Death
 * - bgcolor=FFCC66
 * Finsbury East
 * 29 June 1905
 * Henry Charles Richards
 * Joseph Allen Baker
 * Death
 * North Donegal
 * 15 June 1905
 * William O'Doherty
 * John Muldoon
 * Death
 * Cork City
 * 14 June 1905
 * J. F. X. O'Brien
 * Augustine Roche
 * Death
 * Chichester
 * 2 June 1905
 * Lord Edmund Talbot
 * Lord Edmund Talbot
 * Lord Commissioner of the Treasury
 * - bgcolor=FFCC66
 * Whitby
 * 1 June 1905
 * Ernest Beckett
 * Noel Buxton
 * Succession to peerage
 * - bgcolor=FFCC66
 * Brighton
 * 5 April 1905
 * Gerald Loder
 * Ernest Villiers
 * Lord Commissioner of the Treasury
 * - bgcolor=FFCC66
 * Bute
 * 3 March 1905
 * Andrew Murray
 * Norman Lamont
 * Resignation
 * Appleby
 * 2 March 1905
 * Richard Rigg
 * Leifchild Jones
 * Resignation
 * Liverpool Everton
 * 22 February 1905
 * John A. Willox
 * John Harmood-Banner
 * Resignation
 * North Kildare
 * 14 February 1905
 * Edmund Leamy
 * John O'Connor
 * Death
 * - bgcolor=FFCC66
 * North Dorset
 * 26 January 1905
 * John Wingfield-Digby
 * Arthur Walters Wills
 * Death
 * Mile End
 * 12 January 1905
 * Spencer Charrington
 * Harry Levy-Lawson
 * Death
 * - bgcolor=FFCC66
 * Stalybridge
 * 7 January 1905
 * Matthew White Ridley
 * John Frederick Cheetham
 * Succession to peerage
 * Horsham
 * 11 November 1904
 * John Heywood Johnstone
 * Edward Turnour
 * Death
 * West Monmouthshire
 * 3 November 1904
 * Sir William Harcourt
 * Thomas Richards
 * Death
 * Isle of Thanet
 * 7 October 1904
 * James Lowther
 * Harry Marks
 * Death
 * Cork City
 * 19 August 1904
 * William O'Brien
 * William O'Brien
 * Resignation
 * - bgcolor=FFCC66
 * North East Lanarkshire
 * 10 August 1904
 * William Henry Rattigan
 * Alexander Findlay
 * Death
 * Reading
 * 6 August 1904
 * George William Palmer
 * Rufus Isaacs
 * Resignation
 * - bgcolor=FFCC66
 * Oswestry
 * 26 July 1904
 * George Ormsby-Gore
 * Allan Heywood Bright
 * Succession to peerage
 * Chertsey
 * 6 July 1904
 * John Arthur Fyler
 * Lord Bingham
 * Resignation
 * Sowerby
 * 2 July 1904
 * John William Mellor
 * John Sharp Higham
 * Resignation
 * - bgcolor=FFCC66
 * Devonport
 * 20 June 1904
 * John Lockie
 * John Benn
 * Resignation
 * Harborough
 * 17 June 1904
 * John William Logan
 * Philip Stanhope
 * Resignation
 * West Cavan
 * 11 June 1904
 * Thomas McGovern
 * Vincent Kennedy
 * Death
 * - bgcolor=#c0c0c0
 * Isle of Wight
 * 6 April 1904
 * J. E. B. Seely
 * J. E. B. Seely
 * Resignation on leaving party
 * Dublin St Stephen's Green
 * 21 March 1904
 * James McCann
 * Laurence Ambrose Waldron
 * Death
 * - bgcolor=FFCC66
 * East Dorset
 * 16 March 1904
 * Humphrey Sturt
 * Charles Henry Lyell
 * Succession to peerage
 * Rossendale
 * 15 March 1904
 * Sir William Mather
 * Lewis Harcourt
 * Resignation
 * Normanton
 * 1 March 1904
 * Benjamin Pickard
 * William Parrott
 * Death
 * Birmingham South
 * 26 February 1904
 * Joseph Powell Williams
 * Charles Howard
 * Death
 * - bgcolor=FFCC66
 * St Albans
 * 12 February 1904
 * Vicary Gibbs
 * John Bamford Slack
 * Disqualification for undertaking an Admiralty contract
 * City of London
 * 9 February 1904
 * Alban Gibbs
 * Alban Gibbs
 * Disqualification for undertaking an Admiralty contract
 * - bgcolor=FFCC66
 * Ayr Burghs
 * 30 January 1904
 * Charles Lindsay Orr-Ewing
 * Joseph Dobbie
 * Death
 * Gateshead
 * 20 January 1904
 * William Allan
 * John Johnson
 * Death
 * - bgcolor=FFCC66
 * Norwich
 * 15 January 1904
 * Harry Bullard
 * Louis Tillett
 * Death
 * Ashburton
 * 7 January 1904
 * Charles Seale-Hayne
 * Harry Trelawney Eve
 * Death
 * Ludlow
 * 22 December 1903
 * Robert Jasper More
 * Rowland Hunt
 * Death
 * Lewisham
 * 15 December 1903
 * John Penn
 * Major Edward Coates
 * Death
 * Dulwich
 * 15 December 1903
 * Sir John Blundell Maple
 * Frederick Rutherfoord Harris
 * Death
 * Chorley
 * 4 November 1903
 * Lord Balcarres
 * Lord Balcarres
 * Lord Commissioner of the Treasury
 * Fareham
 * 28 October 1903
 * Arthur Lee
 * Arthur Lee
 * Civil Lord of the Admiralty
 * Westhoughton
 * 24 October 1903
 * Lord Stanley
 * Lord Stanley
 * Postmaster General
 * Warwick and Leamington
 * 23 October 1903
 * Alfred Lyttelton
 * Alfred Lyttelton
 * Secretary of State for the Colonies
 * Belfast West
 * 23 October 1903
 * H. O. Arnold-Forster
 * H. O. Arnold-Forster
 * Secretary of State for War
 * - bgcolor=lightgreen
 * South Meath
 * 9 October 1903
 * James Laurence Carew
 * David Sheehy
 * Death
 * Londonderry
 * 8 October 1903
 * James Hamilton
 * James Hamilton
 * Treasurer of the Household
 * North Leitrim
 * 3 October 1903
 * P. A. McHugh
 * P. A. McHugh
 * Bankruptcy
 * Rochester
 * 22 September 1903
 * James Gascoyne-Cecil
 * Charles Tuff
 * Succession to peerage
 * - bgcolor=FFCC66
 * St Andrews Burghs
 * 17 September 1903
 * Henry Torrens Anstruther
 * Edward Charles Ellice
 * Resignation
 * - bgcolor=FFCC66
 * Argyllshire
 * 26 August 1903
 * Donald Ninian Nicol
 * John Ainsworth
 * Death
 * - bgcolor=pink
 * Barnard Castle
 * 24 July 1903
 * Joseph Pease
 * Arthur Henderson
 * Death
 * South Kildare
 * 23 May 1903
 * Matthew Minch
 * Denis Kilbride
 * Resignation
 * Preston
 * 14 May 1903
 * Robert William Hanbury
 * John Kerr
 * Death
 * Camborne
 * 8 April 1903
 * William Sproston Caine
 * Wilfrid Lawson
 * Death
 * Chertsey
 * 26 March 1903
 * Henry Leigh-Bennett
 * John Arthur Fyler
 * Death
 * - bgcolor=#c0c0c0
 * North Fermanagh
 * 20 March 1903
 * Edward Archdale
 * Edward Mitchell
 * Resignation
 * - bgcolor=FFCC66
 * Rye
 * 17 March 1903
 * Arthur Montagu Brookfield
 * Charles Frederick Hutchinson
 * Resignation
 * - bgcolor=pink
 * Woolwich
 * 11 March 1903
 * Lord Charles Beresford
 * Will Crooks
 * Resignation
 * Galway Borough
 * 9 March 1903
 * Arthur Lynch
 * Charles Ramsay Devlin
 * Disqualification on conviction for high treason
 * Dublin University
 * 5 March 1903
 * William Edward Hartpole Lecky
 * James Campbell
 * Resignation
 * East Perthshire
 * 26 February 1903
 * John Kinloch
 * Thomas Buchanan
 * Resignation
 * South Antrim
 * 5 February 1903
 * William Ellison-Macartney
 * Charles Craig
 * Resignation
 * Liverpool West Derby
 * 20 January 1903
 * Samuel Higginbottom
 * William Rutherford
 * Death
 * - bgcolor=FFCC66
 * Newmarket
 * 2 January 1903
 * Harry McCalmont
 * Charles Day Rose
 * Death
 * - bgcolor=#c0c0c0
 * Orkney and Shetland
 * 18–19 November 1902
 * Cathcart Wason
 * Cathcart Wason
 * Resignation on leaving party
 * Liverpool East Toxteth
 * 6 November 1902
 * Augustus Frederick Warr
 * Austin Taylor
 * Resignation
 * Cleveland
 * 5 November 1902
 * Alfred Pease
 * Herbert Samuel
 * Resignation
 * - bgcolor=lightblue
 * Devonport
 * 22 October 1902
 * E. J. C. Morton
 * John Lockie
 * Death
 * Sevenoaks
 * 21 August 1902
 * Henry Forster
 * Henry Forster
 * Lord Commissioner of the Treasury
 * - bgcolor=#c0c0c0
 * Belfast South
 * 18 August 1902
 * William Johnston
 * Thomas Sloan
 * Death
 * East Worcestershire
 * 15 August 1902
 * Austen Chamberlain
 * Austen Chamberlain
 * Postmaster General
 * Tiverton
 * 14 August 1902
 * William Walrond
 * William Walrond
 * Chancellor of the Duchy of Lancaster
 * - bgcolor=pink
 * Clitheroe
 * 1 August 1902
 * Ughtred Kay-Shuttleworth
 * David Shackleton
 * Elevation to the peerage
 * - bgcolor=FFCC66
 * Leeds North
 * 29 July 1902
 * William Jackson
 * Rowland Barran
 * Elevation to the peerage
 * - bgcolor=FFCC66
 * Bury
 * 10 May 1902
 * James Kenyon
 * George Toulmin
 * Resignation
 * Woolwich
 * 25 April 1902
 * Edwin Hughes
 * Lord Charles Beresford
 * Resignation
 * West Donegal
 * 25 April 1902
 * James Boyle
 * Hugh Law
 * Resignation
 * Wakefield
 * 25 March 1902
 * William Wentworth-FitzWilliam
 * Edward Brotherton
 * Succession to peerage
 * South Monaghan
 * 4 March 1902
 * James Daly
 * John McKean
 * Resignation
 * North Kilkenny
 * 26 February 1902
 * Patrick McDermott
 * Joseph Devlin
 * Resignation
 * South Down
 * 19 February 1902
 * Michael McCartan
 * Jeremiah McVeagh
 * Resignation
 * - bgcolor=#c0c0c0
 * East Down
 * 5 February 1902
 * James Alexander Rentoul
 * James Wood
 * Assistant Judge, City of London Court
 * Sheffield Ecclesall
 * 3 February 1902
 * Ellis Ashmead-Bartlett
 * Samuel Roberts
 * Death
 * Dewsbury
 * 28 January 1902
 * Mark Oldroyd
 * Walter Runciman
 * Resignation
 * Hampstead
 * 24 January 1902
 * Edward Brodie Hoare
 * Thomas Milvain
 * Resignation
 * - bgcolor=lightgreen
 * Galway Borough
 * 21 November 1901
 * Martin Morris
 * Arthur Lynch
 * Succession to peerage
 * - bgcolor=lightblue
 * North East Lanarkshire
 * 26 September 1901
 * John Colville
 * William Henry Rattigan
 * Death
 * Andover
 * 26 August 1901
 * William Wither Bramston Beach
 * Edmund Faber
 * Death
 * Wokingham
 * 12 July 1901
 * Oliver Young
 * Ernest Gardner
 * Resignation
 * Stratford-on-Avon
 * 25 June 1901
 * Victor Milward
 * Philip Staveley Foster
 * Death
 * Saffron Walden
 * 31 May 1901
 * Hon. Armine Wodehouse
 * Jack Pease
 * Death
 * Oswestry
 * 24 May 1901
 * Stanley Leighton
 * George Ormsby-Gore
 * Death
 * Mid Cork
 * 17 May 1901
 * Charles Tanner
 * D. D. Sheehan
 * Death
 * Monmouth
 * 7 May 1901
 * Frederick Rutherfoord Harris
 * Joseph Lawrence
 * Unseated on petition
 * Maidstone
 * 1 March 1901
 * John Barker
 * Sir Francis Evans
 * Void election
 * Stretford
 * 26 February 1901
 * Sir John Maclure
 * Charles Cripps
 * Death
 * North Monaghan
 * 21 December 1900
 * Daniel MacAleese
 * Edward Charles Thompson
 * Death
 * Blackpool
 * 21 December 1900
 * Sir Matthew White Ridley
 * Henry Worsley-Taylor
 * Elevation to the peerage
 * West Derbyshire
 * 11 December 1900
 * Victor Cavendish
 * Victor Cavendish
 * Treasurer of the Household
 * Woodbridge
 * 10 December 1900
 * E. G. Pretyman
 * E. G. Pretyman
 * Civil Lord of the Admiralty
 * Wellington (Somerset)
 * 10 December 1900
 * Alexander Acland-Hood
 * Alexander Acland-Hood
 * Vice-Chamberlain of the Household
 * Guildford
 * 10 December 1900
 * St John Broderick
 * St John Broderick
 * Secretary of State for War
 * Preston
 * 8 December 1900
 * Robert William Hanbury
 * Robert William Hanbury
 * President of the Board of Agriculture
 * Dover
 * 8 December 1900
 * George Wyndham
 * George Wyndham
 * Chief Secretary for Ireland
 * colspan=9 |
 * Augustus Frederick Warr
 * Austin Taylor
 * Resignation
 * Cleveland
 * 5 November 1902
 * Alfred Pease
 * Herbert Samuel
 * Resignation
 * - bgcolor=lightblue
 * Devonport
 * 22 October 1902
 * E. J. C. Morton
 * John Lockie
 * Death
 * Sevenoaks
 * 21 August 1902
 * Henry Forster
 * Henry Forster
 * Lord Commissioner of the Treasury
 * - bgcolor=#c0c0c0
 * Belfast South
 * 18 August 1902
 * William Johnston
 * Thomas Sloan
 * Death
 * East Worcestershire
 * 15 August 1902
 * Austen Chamberlain
 * Austen Chamberlain
 * Postmaster General
 * Tiverton
 * 14 August 1902
 * William Walrond
 * William Walrond
 * Chancellor of the Duchy of Lancaster
 * - bgcolor=pink
 * Clitheroe
 * 1 August 1902
 * Ughtred Kay-Shuttleworth
 * David Shackleton
 * Elevation to the peerage
 * - bgcolor=FFCC66
 * Leeds North
 * 29 July 1902
 * William Jackson
 * Rowland Barran
 * Elevation to the peerage
 * - bgcolor=FFCC66
 * Bury
 * 10 May 1902
 * James Kenyon
 * George Toulmin
 * Resignation
 * Woolwich
 * 25 April 1902
 * Edwin Hughes
 * Lord Charles Beresford
 * Resignation
 * West Donegal
 * 25 April 1902
 * James Boyle
 * Hugh Law
 * Resignation
 * Wakefield
 * 25 March 1902
 * William Wentworth-FitzWilliam
 * Edward Brotherton
 * Succession to peerage
 * South Monaghan
 * 4 March 1902
 * James Daly
 * John McKean
 * Resignation
 * North Kilkenny
 * 26 February 1902
 * Patrick McDermott
 * Joseph Devlin
 * Resignation
 * South Down
 * 19 February 1902
 * Michael McCartan
 * Jeremiah McVeagh
 * Resignation
 * - bgcolor=#c0c0c0
 * East Down
 * 5 February 1902
 * James Alexander Rentoul
 * James Wood
 * Assistant Judge, City of London Court
 * Sheffield Ecclesall
 * 3 February 1902
 * Ellis Ashmead-Bartlett
 * Samuel Roberts
 * Death
 * Dewsbury
 * 28 January 1902
 * Mark Oldroyd
 * Walter Runciman
 * Resignation
 * Hampstead
 * 24 January 1902
 * Edward Brodie Hoare
 * Thomas Milvain
 * Resignation
 * - bgcolor=lightgreen
 * Galway Borough
 * 21 November 1901
 * Martin Morris
 * Arthur Lynch
 * Succession to peerage
 * - bgcolor=lightblue
 * North East Lanarkshire
 * 26 September 1901
 * John Colville
 * William Henry Rattigan
 * Death
 * Andover
 * 26 August 1901
 * William Wither Bramston Beach
 * Edmund Faber
 * Death
 * Wokingham
 * 12 July 1901
 * Oliver Young
 * Ernest Gardner
 * Resignation
 * Stratford-on-Avon
 * 25 June 1901
 * Victor Milward
 * Philip Staveley Foster
 * Death
 * Saffron Walden
 * 31 May 1901
 * Hon. Armine Wodehouse
 * Jack Pease
 * Death
 * Oswestry
 * 24 May 1901
 * Stanley Leighton
 * George Ormsby-Gore
 * Death
 * Mid Cork
 * 17 May 1901
 * Charles Tanner
 * D. D. Sheehan
 * Death
 * Monmouth
 * 7 May 1901
 * Frederick Rutherfoord Harris
 * Joseph Lawrence
 * Unseated on petition
 * Maidstone
 * 1 March 1901
 * John Barker
 * Sir Francis Evans
 * Void election
 * Stretford
 * 26 February 1901
 * Sir John Maclure
 * Charles Cripps
 * Death
 * North Monaghan
 * 21 December 1900
 * Daniel MacAleese
 * Edward Charles Thompson
 * Death
 * Blackpool
 * 21 December 1900
 * Sir Matthew White Ridley
 * Henry Worsley-Taylor
 * Elevation to the peerage
 * West Derbyshire
 * 11 December 1900
 * Victor Cavendish
 * Victor Cavendish
 * Treasurer of the Household
 * Woodbridge
 * 10 December 1900
 * E. G. Pretyman
 * E. G. Pretyman
 * Civil Lord of the Admiralty
 * Wellington (Somerset)
 * 10 December 1900
 * Alexander Acland-Hood
 * Alexander Acland-Hood
 * Vice-Chamberlain of the Household
 * Guildford
 * 10 December 1900
 * St John Broderick
 * St John Broderick
 * Secretary of State for War
 * Preston
 * 8 December 1900
 * Robert William Hanbury
 * Robert William Hanbury
 * President of the Board of Agriculture
 * Dover
 * 8 December 1900
 * George Wyndham
 * George Wyndham
 * Chief Secretary for Ireland
 * colspan=9 |
 * Jack Pease
 * Death
 * Oswestry
 * 24 May 1901
 * Stanley Leighton
 * George Ormsby-Gore
 * Death
 * Mid Cork
 * 17 May 1901
 * Charles Tanner
 * D. D. Sheehan
 * Death
 * Monmouth
 * 7 May 1901
 * Frederick Rutherfoord Harris
 * Joseph Lawrence
 * Unseated on petition
 * Maidstone
 * 1 March 1901
 * John Barker
 * Sir Francis Evans
 * Void election
 * Stretford
 * 26 February 1901
 * Sir John Maclure
 * Charles Cripps
 * Death
 * North Monaghan
 * 21 December 1900
 * Daniel MacAleese
 * Edward Charles Thompson
 * Death
 * Blackpool
 * 21 December 1900
 * Sir Matthew White Ridley
 * Henry Worsley-Taylor
 * Elevation to the peerage
 * West Derbyshire
 * 11 December 1900
 * Victor Cavendish
 * Victor Cavendish
 * Treasurer of the Household
 * Woodbridge
 * 10 December 1900
 * E. G. Pretyman
 * E. G. Pretyman
 * Civil Lord of the Admiralty
 * Wellington (Somerset)
 * 10 December 1900
 * Alexander Acland-Hood
 * Alexander Acland-Hood
 * Vice-Chamberlain of the Household
 * Guildford
 * 10 December 1900
 * St John Broderick
 * St John Broderick
 * Secretary of State for War
 * Preston
 * 8 December 1900
 * Robert William Hanbury
 * Robert William Hanbury
 * President of the Board of Agriculture
 * Dover
 * 8 December 1900
 * George Wyndham
 * George Wyndham
 * Chief Secretary for Ireland
 * colspan=9 |
 * Woodbridge
 * 10 December 1900
 * E. G. Pretyman
 * E. G. Pretyman
 * Civil Lord of the Admiralty
 * Wellington (Somerset)
 * 10 December 1900
 * Alexander Acland-Hood
 * Alexander Acland-Hood
 * Vice-Chamberlain of the Household
 * Guildford
 * 10 December 1900
 * St John Broderick
 * St John Broderick
 * Secretary of State for War
 * Preston
 * 8 December 1900
 * Robert William Hanbury
 * Robert William Hanbury
 * President of the Board of Agriculture
 * Dover
 * 8 December 1900
 * George Wyndham
 * George Wyndham
 * Chief Secretary for Ireland
 * colspan=9 |
 * Robert William Hanbury
 * Robert William Hanbury
 * President of the Board of Agriculture
 * Dover
 * 8 December 1900
 * George Wyndham
 * George Wyndham
 * Chief Secretary for Ireland
 * colspan=9 |
 * George Wyndham
 * Chief Secretary for Ireland
 * colspan=9 |
 * Chief Secretary for Ireland
 * colspan=9 |
 * colspan=9 |
 * }