# List of Western Australian state by-elections

The list of Western Australia state by-elections includes every by-election held in the Australian state of Western Australia. By-elections occur whenever there is a vacancy in the Legislative Assembly (or, historically, the Legislative Council), although an imminent state election may allow the vacancy to remain until the dissolution of parliament.
Section 67 of the Electoral Act 1907 requires the Speaker to issue a writ for a by-election to fill the vacancy. This can either take place after a resolution of the House if Parliament is in session, or simply upon the cause being established by the Speaker acting alone if the Parliament is in adjournment for more than seven days.

## Causes

A by-election occurs whenever there is a vacancy in the Legislative Assembly. Vacancies can occur for the following reasons, according to Section 38 of the Constitution Acts Amendment Act 1899.
The member:
* Is no longer eligible to sit—for example, leaving the State. This historically occurred more frequently when times were less economically stable, and people would move to another state or country where they could work or conduct business.
* Has been convicted for an offence for which the penalty was imprisonment for life, or for more than five years (Section 32). This last happened to John Marquis Hopkins when he was convicted for fraud in 1910, necessitating a by-election in his seat of Beverley.
* Becomes an undischarged bankrupt. This last happened in 1936 when Independent candidate Thomas Hughes won East Perth against the incumbent member in the 1936 election. However it was found that he was an undischarged bankrupt at the time of the nomination and poll (although had since resolved his affairs), and the election was declared void. He won the resulting by-election.
* Is elected to either the Federal Parliament or the parliament of another state or territory (Section 34). In practice, this is never necessary, as the other Parliament usually requires resignation from the Western Australian parliament in order to nominate as a candidate. This last occurred in the Legislative Assembly in 2001 when Hendy Cowan, the member for Merredin, resigned to unsuccessfully contest a seat in the Australian Senate.
* Is appointed as a judge or magistrate in a Western Australian court or as a chairman (or in some cases member) of another state board or tribunal (Section 34). This provision has never been acted upon, although numerous members have resigned over time to take up such an appointment—for example, Ron Davies resigned in Victoria Park in 1986 to become Agent-General for Western Australia in London, whilst Deputy Premier Herb Graham resigned in Balcatta in 1973 to become chairman of the Licensing Board.
* "Holds an office or place in the service of the Crown" at the time at which they take up their seat (Section 36-37). This has never been used at state level, although it has occurred in other States and in the Federal Parliament (for example, the circumstances leading to the federal Lindsay by-election in 1996.)
* Becomes "of unsound mind".
* Pledges allegiance to a foreign power after their election. This does not apply to members who are already dual citizens at the time of their election, unlike the equivalent section in the Federal Constitution.
* Fails to attend the House for one entire session without the permission of the House. The last time this caused a by-election was in 1915 when Joseph Gardiner, the Labor member for Roebourne, disappeared, necessitating a by-election in which an Opposition candidate was victorious, wiping out the Government's one-seat majority.
Additional reasons not within Section 38 include death, resignation, or the voiding of results by a Court of Disputed Returns. The last time a by-election took place for this reason was in 1983, when Gavan Troy, the Labor candidate, narrowly defeated incumbent Liberal member Tom Herzfeld in Mundaring. The seat was won by Troy by a larger margin at the resulting by-election.

### Ministerial by-elections

Until a constitutional amendment in 1947, it was necessary for members who were appointed as a minister to resign their seat and contest their seat at a ministerial by-election. This was because the ministers became members of the executive council, which reported to the governor of Western Australia and was therefore deemed an "office of profit" under the Crown. Most ministerial by-elections were a formality with the minister being re-elected unopposed, but on two occasions, in 1901 and 1917, ministers were defeated at the by-elections, in the former case directly causing the fall of the Morgans Ministry.

## List of Legislative Assembly by-elections
### 2020–2029

| Parl. | By-election | Date | Incumbent | Party | Party | Winner | Party | Party | Vacated | Cause | Retained |
| 41st | Rockingham | 29 July 2023 | Mark McGowan | | Labor | Magenta Marshall | | Labor | 8 June 2023 | Resignation | Yes |
| 41st | North West Central | 17 September 2022 | Vince Catania | | National | Merome Beard | | National | 8 August 2022 | Resignation | Yes |

### 2010–2019

| Parl. | By-election | Date | Incumbent | Party | Winner | Party | Vacated | Cause | Retained |
| 40th | Darling Range | 23 June 2018 | Barry Urban | Independent | Alyssa Hayden | Liberal | 8 May 2018 | Resignation | No |
| 40th | Cottesloe | 17 March 2018 | Colin Barnett | Liberal | David Honey | Liberal | 5 February 2018 | Resignation | Yes |
| 39th | Vasse | 18 October 2014 | Troy Buswell | Liberal | Libby Mettam | Liberal | 3 September 2014 | Resignation | Yes |
| 38th | Armadale | 2 October 2010 | Alannah MacTiernan | Labor | Tony Buti | Labor | 19 July 2010 | Resignation (Contesting HoR) | Yes |

### 2000–2009

| Parl. | By-election | Date | Incumbent | Party | Winner | Party | Vacated | Cause | Retained |
| 38th | Willagee | 28 November 2009 | Alan Carpenter | Labor | Peter Tinley | Labor | 2 October 2009 | Resignation | Yes |
| 38th | Fremantle | 16 May 2009 | Jim McGinty | Labor | Adele Carles | Greens | 3 April 2009 | Resignation | No |
| 37th | Murdoch | 23 February 2008 | Trevor Sprigg | Liberal | Christian Porter | Liberal | 17 January 2008 | Death | Yes |
| 37th | Peel | 3 February 2007 | Norm Marlborough | Labor | Paul Papalia | Labor | 10 November 2006 | Resignation | Yes |
| 37th | Victoria Park | 11 March 2006 | Dr Geoff Gallop | Labor | Ben Wyatt | Labor | 16 January 2006 | Resignation | Yes |
| 36th | Merredin | 24 November 2001 | Hendy Cowan | National | Brendon Grylls | National | 17 October 2001 | Resignation (contesting Senate) | Yes |
| 36th | Nedlands | 9 June 2001 | Richard Court | Liberal | Sue Walker | Liberal | 23 February 2001 | Resignation | Yes |

### 1990–1999

| Parl. | By-election | Date | Incumbent | Party | Winner | Party | Vacated | Cause | Retained |
| 34th | Kalgoorlie | 16 March 1996 | Ian Taylor | Labor | Megan Anwyl | Labor | 4 February 1996 | Resignation (contesting HoR) | Yes |
| 34th | Helena | 10 September 1994 | Gordon Hill | Labor | Rhonda Parker | Liberal | 4 August 1994 | Resignation | No |
| 34th | Glendalough | 19 March 1994 | Dr Carmen Lawrence | Labor | Michelle Roberts | Labor | 14 February 1994 | Resignation (contesting HoR) | Yes |
| 33rd | Ashburton | 4 April 1992 | Pam Buchanan | Independent | Fred Riebeling | Labor | 3 March 1992 | Resignation (ill health) | Yes |
| 33rd | Floreat | 20 July 1991 | Andrew Mensaros | Liberal | Liz Constable | Independent | May 1991 | Resignation (ill health) | No |
| 33rd | Geraldton | 13 April 1991 | Jeff Carr | Labor | Bob Bloffwitch | Liberal | 28 February 1991 | Resignation | No |
| 33rd | Cottesloe | 11 August 1990 | Bill Hassell | Liberal | Colin Barnett | Liberal | 28 June 1990 | Resignation | Yes |
| 33rd | Maylands | 26 May 1990 | Peter Dowding | Labor | Judy Edwards | Labor | 26 April 1990 | Resignation | Yes |
| 33rd | Fremantle | 26 May 1990 | David Parker | Labor | Jim McGinty | Labor | 26 April 1990 | Resignation | Yes |
    $^1$ The Independent member for Ashburton, Pam Buchanan, was elected at the 1989 state election as a member of the Labor Party, but resigned on 1 February 1991 to sit as an Independent. As such, the 1992 by-election is noted as a retain for Labor.

### 1980–1989

| Parl. | By-election | Date | Incumbent | Party | Winner | Party | Vacated | Cause | Retained |
| 32nd | Dale | 7 May 1988 | Cyril Rushton | Liberal | Fred Tubby | Liberal | 25 February 1988 | Resignation | Yes |
| 32nd | Ascot | 19 March 1988 | Mal Bryce | Labor | Eric Ripper | Labor | 17 February 1988 | Resignation | Yes |
| 32nd | Balga | 19 March 1988 | Brian Burke | Labor | Ted Cunningham | Labor | 17 February 1988 | Resignation | Yes |
| 32nd | Darling Range | 24 October 1987 | George Spriggs | Liberal | Bob Greig | Liberal | 3 September 1987 | Resignation | Yes |
| 32nd | Gascoyne | 24 October 1987 | Ian Laurance | Liberal | Dudley Maslen | Liberal | 3 September 1987 | Resignation | Yes |
| 32nd | Morley-Swan | 9 May 1987 | Arthur Tonkin | Labor | Frank Donovan | Labor | 18 March 1987 | Resignation | Yes |
| 32nd | Narrogin | 9 May 1987 | Cambell Nalder | National | Bob Wiese | National | 14 March 1987 | Death | Yes |
| 32nd | Perth | 9 May 1987 | Terry Burke | Labor | Dr Ian Alexander | Labor | 18 March 1987 | Resignation | Yes |
| 32nd | Cockburn | 7 June 1986 | Clive Hughes | Labor | Norm Marlborough | Labor | 4 April 1986 | Death | Yes |
| 32nd | Victoria Park | 7 June 1986 | Ron Davies | Labor | Dr Geoff Gallop | Labor | 16 April 1986 | Resignation (appointed as Agent-General) | Yes |
| 31st | Cockburn | 17 November 1984 | Don Taylor | Labor | Clive Hughes | Labor | 31 August 1984 | Resignation | Yes |
| 31st | Mount Lawley | 17 November 1984 | Ray O'Connor | Liberal | George Cash | Liberal | 17 August 1984 | Resignation | Yes |
| 31st | Mundaring | 8 October 1983 | Gavan Troy | Labor | Gavan Troy | Labor | 2 September 1983 | Voided by Court of Disputed Returns | Yes |
| 30th | Nedlands | 13 March 1982 | Sir Charles Court | Liberal | Richard Court | Liberal | 31 January 1982 | Resignation | Yes |
| 30th | Swan | 13 March 1982 | Jack Skidmore | Labor | Gordon Hill | Labor | 31 January 1982 | Resignation | Yes |
| 30th | Kalgoorlie | 20 June 1981 | Ted Evans | Labor | Ian Taylor | Labor | 30 April 1981 | Death | Yes |

### 1970–1979

| Parl. | By-election | Date | Incumbent | Party | Winner | Party | Vacated | Cause | Retained |
| 29th | Kimberley | 17 December 1977 | Alan Ridge | Liberal | Alan Ridge | Liberal | 7 November 1977 | Voided by Court of Disputed Returns | Yes |
| 28th | Greenough | 1 November 1975 | Sir David Brand | Liberal | Reg Tubby | Liberal | 21 August 1975 | Resignation | Yes |
| 27th | Balcatta | 28 July 1973 | Herb Graham | Labor | Brian Burke | Labor | 30 May 1973 | Resignation (appointed to Licensing Court) | Yes |
| 27th | Bunbury | 7 April 1973 | Maurice Williams | Liberal | John Sibson | Liberal | 28 February 1973 | Resignation | Yes |
| 27th | Blackwood | 16 December 1972 | David Reid | Country | Sandy Lewis | Liberal | 26 October 1972 | Resignation (contesting HoR) | No |
| 27th | Ascot | 13 November 1971 | Merv Toms | Labor | Mal Bryce | Labor | 8 October 1971 | Death | Yes |
| 26th | Albany | 6 June 1970 | Jack Hall | Labor | Wyndham Cook | Labor | 14 April 1970 | Resignation | Yes |

### 1960–1969

| Parl. | By-election | Date | Incumbent | Party | Winner | Party | Vacated | Cause | Retained |
| 25th | Mount Marshall | 2 September 1967 | George Cornell | Country | Ray McPharlin | Country | 6 July 1967 | Death | Yes |
| 25th | Roe | 2 September 1967 | Tom Hart | Country | Bill Young | Country | 30 June 1967 | Resignation | Yes |
| 25th | Dale | 8 May 1965 | Gerald Wild | Liberal | Cyril Rushton | Liberal | 16 March 1965 | Resignation (appointed as Agent-General) | Yes |
| 24th | Bunbury | 1 September 1962 | George Roberts | Liberal | Maurice Williams | Liberal | 22 July 1962 | Death | Yes |
| 24th | Darling Range | 21 July 1962 | Ken Dunn | Liberal | Ken Dunn | Liberal | 22 June 1962 | Voided by Court of Disputed Returns | Yes |
| 24th | Murray | 23 June 1962 | Sir Ross McLarty | Liberal | Ewart Runciman | Liberal | 7 May 1962 | Resignation | Yes |
| 23rd | Victoria Park | 26 August 1961 | Hugh Andrew | Labor | Ron Davies | Labor | 1 July 1961 | Death | Yes |
| 23rd | South Fremantle | 12 March 1960 | Dick Lawrence | Labor | Henry Curran | Labor | 25 January 1960 | Death | Yes |

### 1950–1959

| Parl. | By-election | Date | Incumbent | Party | Winner | Party | Vacated | Cause | Retained |
| 22nd | Moore | 20 September 1958 | John Ackland | Country | Edgar Lewis | Country | 29 July 1958 | Death | Yes |
| 22nd | Pilbara | 24 April 1958† | Aloysius Rodoreda | Labor | Arthur Bickerton | Labor | 11 March 1958 | Death | Yes |
| 22nd | Warren | 25 January 1958 | Ernest Hoar | Labor | Joseph Rowberry | Labor | 17 December 1957 | Resignation (appointed as Agent-General) | Yes |
| 21st | Bunbury | 29 October 1955 | Frank Guthrie | Labor | George Roberts | Liberal | 21 September 1955 | Death | No |
| 21st | Kimberley | 16 May 1953 | Aubrey Coverley | Labor | John Rhatigan | Labor | 19 March 1953 | Death | Yes |
| 20th | Murchison | 8 November 1952 | William Marshall | Labor | Everard O'Brien | Labor | 19 August 1952 | Death | Yes |
| 20th | Leederville | 9 February 1952 | Alexander Panton | Labor | Ted Johnson | Labor | 25 December 1951 | Death | Yes |
| 20th | Gascoyne | 13 October 1951 | Frank Wise | Labor | Noel Butcher | Ind. Lib. | 9 July 1951 | Resignation (appointed as NT Administrator) | No |
| 20th | Boulder | 14 September 1951† | Charlie Oliver | Labor | Arthur Moir | Labor | 16 August 1951 | Death | Yes |
| 20th | South Fremantle | 14 July 1951 | Tom Fox | Labor | Dick Lawrence | Labor | 20 April 1951 | Death | Yes |
| 20th | Maylands | 17 February 1951 | Harry Shearn | Independent | Edward Oldfield | Liberal | 25 January 1951 | Death | No |
† Won by acclamation; this date is the date of the return of the writ.

### 1940–1949

| Parl. | By-election | Date | Incumbent | Party | Winner | Party | Vacated | Cause | Retained |
| 19th | Hannans | 26 February 1949 | David Leahy | Labor | Harry McCulloch | Labor | 19 December 1948 | Death | Yes |
| 19th | Boulder | 4 December 1948 | Hon Philip Collier | Labor | Charlie Oliver | Labor | 18 October 1948 | Death | Yes |
| 19th | Guildford-Midland | 13 March 1948 | William Johnson | Labor | John Brady | Labor | 26 January 1948 | Death | Yes |
| 19th | Sussex | 7 June 1947 | William Willmott | Liberal | Stewart Bovell | Liberal | 2 May 1947 | Death | Yes |
| 19th | Pilbara | 2 August 1947 | Bill Hegney | Labor | Bill Hegney | Labor | 20 June 1947 | Voided by petition | Yes |
| 18th | Greenough | 27 October 1945 | John Newton | Labor | David Brand | Liberal | 27 September 1945 | Death (WWII combat) | No |
| 18th | Victoria Park | 10 February 1945 | Howard Raphael | Labor | William Read | Independent | 9 December 1944 | Death | No |
| 18th | Avon | 1 July 1944 | William Telfer | Labor | William Telfer | Labor | 24 May 1944 | Voided by Court of Disputed Returns | Yes |
| 18th | Swan | 29 April 1944 | Richard Sampson | Country | Ray Owen | Ind. Country | 16 February 1944 | Death | No |
| 17th | East Perth | 14 August 1943 | Thomas Hughes | Independent | Herb Graham | Labor | 15 July 1943 | Resignation (contesting HoR) | No |
| 17th | York | 21 November 1942 | Charles Latham | Country | Charles Perkins | Country | 7 October 1942 | Resignation (appointed to Senate) | Yes |
| 17th | Yilgarn-Coolgardie | 9 August 1941 | George Lambert | Labor | Lionel Kelly | Ind. Country | 30 June 1941 | Death | No |
    $^2$ At the 1943 election, the Labor candidate for Greenough, John Newton, a farmer from Mingenew who had enlisted in the RAAF as a Flight Lieutenant in 1941 and left for the United Kingdom in 1942, unexpectedly defeated the sitting Country member, William Patrick. On 14 January 1944, he was reported missing after a raid on Germany. On 31 July 1945, a panel of members was appointed to enquire whether a vacancy existed, and on 27 September 1945, the seat was declared vacant. At the resulting by-election on 27 October 1945, Liberal candidate David Brand was successful, becoming the first person to win an Australian election under the new Liberal banner.

### 1930–1939

| Parl. | By-election | Date | Incumbent | Party | Winner | Party | Vacated | Cause | Retained |
| 17th | Irwin-Moore | 9 September 1939 | Claude Barker | Independent | Horace Berry | Independent | 2 August 1939 | Resignation | Yes |
| 17th | Forrest | 20 May 1939 | May Holman | Labor | Edward Holman | Labor | 20 March 1939 | Death (car accident) | Yes |
| 16th | Hannans | 5 May 1938 | Selby Munsie | Labor | David Leahy | Labor | 12 March 1938 | Death | Yes |
| 16th | Sussex | 12 February 1938 | Edmund Brockman | Nationalist | William Willmott | Nationalist | 4 January 1938 | Death | Yes |
| 16th | East Perth | 9 May 1936 | Thomas Hughes | Independent | Thomas Hughes | Independent | 18 April 1936 | Resignation | Yes |
| 15th | Katanning | 31 August 1935 | Arnold Piesse | Country | Arthur Watts | Country | 21 July 1935 | Death | Yes |
| 15th | Avon | 4 July 1935 | Harry Griffiths | Country | Ignatius Boyle | Country | 23 March 1935 | Death | Yes |
| 15th | South Fremantle | 4 July 1935 | Alick McCallum | Labor | Tom Fox | Labor | 16 March 1935 | Resignation | Yes |
| 15th | Kimberley | 29 July 1933 | Aubrey Coverley | Labor | Aubrey Coverley | Labor | 3 July 1933 | Voided by Court of Disputed Returns | Yes |
| 14th | Brown Hill-Ivanhoe | 14 July 1932† | John Lutey | Labor | Frederick Smith | Labor | 22 June 1932 | Death | Yes |
| 14th | Kanowna | 25 June 1932 | Thomas Walker | Labor | Emil Nulsen | Labor | 10 May 1932 | Death | Yes |
| 14th | Roebourne | 6 February 1932 | Frederick Teesdale | Nationalist | John Church | Nationalist | 14 December 1931 | Death | Yes |
† Won by acclamation; this date is the date of the return of the writ.

### 1920–1929

| Parl. | By-election | Date | Incumbent | Party | Winner | Party | Vacated | Cause | Retained |
| 13th | Irwin | 19 November 1929 | Charles Maley | Country | Henry Maley | Country | 15 October 1929 | Death | Yes |
| 13th | Mount Leonora | 7 November 1928† | Thomas Heron | Labor | Ernest Cowan | Labor | 13 October 1928 | Death | Yes |
| 13th | Williams-Narrogin | 3 November 1928† | Bertie Johnston | Country | Victor Doney | Country | 3 October 1928 | Resignation (contesting Senate) | Yes |
| 12th | Forrest | 3 April 1925† | John Holman | Labor | May Holman | Labor | 23 February 1925 | Death | Yes |
| 11th | Forrest | 8 December 1923 | Peter O'Loghlen | Labor | John Holman | Labor | 12 November 1923 | Death | Yes |
| 11th | Kalgoorlie | 13 January 1923 | John Boyland | Independent | James Cunningham | Labor | 14 December 1922 | Death | No |
| 11th | East Perth | 18 November 1922 | Jack Simons | Nationalist | Thomas Hughes | Labor | 1 November 1922 | Resignation | No |
| 10th | Mount Leonora | 20 December 1920 | George Foley | National Labor | Thomas Heron | Labor | 18 November 1920 | Resignation (contesting HoR) | No |
    $^3$ Simons had been elected as a Labor member in the 1921 state election, but had resigned to sit as an independent and subsequently joined the Nationalist Party. He was a candidate in the by-election, but was defeated.
† Won by acclamation; this date is the date of the return of the writ.

### 1910–1919

| Parl. | By-election | Date | Incumbent | Party | Winner | Party | Vacated | Cause | Retained |
| 10th | Albany | 31 May 1919 | Herbert Robinson | Nationalist | John Scaddan | National Labor | 2 May 1919 | Death | No |
| 10th | Claremont | 14 September 1918 | John Stewart | Nationalist | Thomas Duff | Nationalist | 30 August 1918 | Resignation | Yes |
| 10th | Subiaco | 10 November 1917 | Bartholomew Stubbs | Labor | Samuel Brown | Nationalist | 26 September 1917 | Death (WWI combat) | No |
| 9th | Perth | 21 July 1917 | Sir James Connolly | Nationalist | Robert Pilkington | Nationalist | June 1917 | Resignation | Yes |
| 9th | Brown Hill-Ivanhoe | 21 July 1917 | John Scaddan | National Labor | John Lutey | Labor | 28 June 1917 | Ministerial by-election | No |
| 9th | Geraldton | 14 April 1917 | Edward Heitmann | National Labor | Samuel Elliott | Liberal | 20 March 1917 | Resignation (contesting HoR) | No |
| 9th | Brown Hill-Ivanhoe | 7 October 1916 | John Lutey | Labor | John Scaddan | Labor | 15 September 1916 | Resignation | Yes |
| 9th | Brown Hill-Ivanhoe | 19 August 1916† | John Scaddan | Labor | John Lutey | Labor | 8 August 1916 | Resignation | Yes |
| 9th | Coolgardie | 15 August 1916 | Charles McDowall | Labor | George Lambert | Labor | 13 July 1916 | Death | Yes |
| 9th | Williams-Narrogin | 9 January 1916† | Bertie Johnston | Independent | Bertie Johnston | Independent | 18 December 1915 | Resignation | Yes |
| 9th | Roebourne | 17 November 1915 | Joseph Gardiner | Labor | William Butcher | Liberal | 30 September 1915 | Absence without leave | No |
| 8th | Kalgoorlie | 4 February 1914 | Albert Green | Labor | George McLeod | Labor | 8 December 1913 | Resignation | Yes |
| 8th | Geraldton | 15 November 1913 | Bronte Dooley | Labor | Samuel Elliott | Liberal | 19 October 1913 | Death | No |
| 8th | Cue | 12 November 1913† | Edward Heitmann | Labor | Thomas Chesson | Labor | 4 November 1913 | Resignation | Yes |
| 8th | Forrest | 3 July 1913 | Thomas Moore | Labor | Peter O'Loghlen | Labor | 17 June 1913 | Resignation | Yes |
| 8th | Forrest | 6 May 1913† | Peter O'Loghlen | Labor | Thomas Moore | Labor | 17 April 1913 | Resignation (contesting HoR) | Yes |
| 7th | Bunbury | 1 March 1911 | Sir Newton Moore | Ministerial | William Thomas | Labor | 13 February 1911 | Resignation (appointed as Agent-General) | No |
| 7th | Beverley | 15 August 1910 | John Hopkins | Ministerial | Nat Harper | Ministerial | 28 July 1910 | Disqualified (jailed for uttering) | Yes |
| 7th | Forrest | 8 July 1910 | Dennis Jones | Labor | Peter O'Loghlen | Labor | 20 June 1910 | Resignation | Yes |
| 7th | Gascoyne | 28 June 1910† | William Butcher | Ministerial | William Butcher | Ministerial | 18 June 1910 | Sold land to Crown | Yes |
| 7th | Fremantle | 9 June 1910 | James Price | Ministerial | William Murphy | Ministerial | 21 May 1910 | Death | Yes |
| 7th | Forrest | 23 March 1910† | Peter O'Loghlen | Labor | Dennis Jones | Labor | 13 March 1910 | Resignation (contesting HoR) | Yes |
† Won by acclamation; this date is the date of the return of the writ.
    $^4$ The Labor member for Brown Hill-Ivanhoe and former premier, John Scaddan, resigned from his seat on 8 August 1916 in order to contest the Canning ministerial by-election against new minister Robert Robinson. On 19 August 1916, Labor candidate John Lutey was elected unopposed to fill the vacancy. However, upon Scaddan's narrow loss in Canning, Lutey resigned from the seat on 15 September 1916 before being sworn in to allow Scaddan to regain his seat, which he did at the resulting by-election on 7 October 1916 against two minor-party candidates. In March 1917, Scaddan and several others left the Labor Party and joined the new National Labor Party. This party formed a coalition with the Nationalists who, under Premier Sir Henry Lefroy, formed a Ministry on 28 June 1917. Scaddan was appointed minister for railways, and had to contest a ministerial by-election. John Lutey won the seat at the by-election on 21 July 1917.
    $^5$ On 18 December 1915, the Labor member for Williams-Narrogin, Bertie Johnston, resigned from the Labor Party and from Parliament. He was returned unopposed as an Independent at the close of nominations for the resulting by-election on 9 January 1916. In mid-1917, he joined the Country Party.

### 1900–1909

| Parl. | By-election | Date | Incumbent | Party | Winner | Party | Vacated | Cause | Retained |
| 7th | Katanning | 12 November 1909† | Frederick Henry Piesse | Ministerial | Arnold Piesse | Ministerial | 26 October 1909 | Resignation | Yes |
| 7th | Albany | 17 September 1909 | Edward Barnett | Ministerial | William Price | Ministerial | Aug/Sep 1909 | Resignation | Yes |
| 7th | Menzies | 20 November 1908 | Henry Gregory | Ministerial | Henry Gregory | Ministerial | 4 November 1908 | Voided by petition | Yes |
| 6th | West Perth | 2 September 1907 | Frederick Illingworth | Ministerial | Thomas Draper | NPL (Min.) | 13 August 1907 | Resignation | Yes |
| 6th | Mount Leonora | 13 November 1906† | Patrick Lynch | Labor | Julian Stuart | Labor | 2 November 1906 | Resignation (contesting Senate) | Yes |
| 6th | Geraldton | 21 November 1906 | Henry Carson | Ministerial | Thomas Brown | Labor | 26 October 1906 | Voided by petition | No |
| 6th | East Fremantle | 13 November 1906 | Joseph Holmes | Ministerial | William Angwin | Labor | 24 October 1906 | Voided by petition | No |
| 6th | Pilbara | 23 July 1906 | James Isdell | Independent | Henry Underwood | Labor | 27 June 1906 | Resignation | No |
| 6th | Guildford | 16 July 1906 | Sir Cornthwaite Rason | Ministerial | William Johnson | Labor | 27 June 1906 | Resignation (appointed as Agent-General) | No |
| 6th | South Fremantle | 16 July 1906 | Arthur Diamond | Ministerial | Arthur Davies | Ministerial | 22 June 1906 | Death | Yes |
| 6th | Coolgardie | 9 July 1906 | William Eddy | Ministerial | William Eddy | Ministerial | 27 April 1906 | Voided by petition | Yes |
| 5th | East Perth | 20 October 1904 | Walter James | Ministerial | John Hardwick | Ministerial | 4 October 1904 | Resignation (appointed as Agent-General) | Yes |
| 4th | Nelson | 11 December 1903 | Sir J. G. Lee-Steere | Ministerial | John Walter | Ministerial | 30 November 1903 | Death | Yes |
| 4th | North Fremantle | 26 August 1903 | Denis Doherty | Ministerial | John Ferguson | Ministerial | 13 August 1903 | Resignation (left State) | Yes |
| 4th | York | 6 April 1903 | Frederick Monger | Ministerial | R. G. Burges | Ministerial | 24 March 1903 | Resignation | Yes |
| 4th | Pilbara | 18 March 1903 | Walter Kingsmill | Opposition | James Isdell | Independent | 12 February 1903 | Resignation | No |
| 4th | Hannans | 15 October 1902† | John Reside | Labor | Thomas Bath | Labor | 29 September 1902 | Death | Yes |
| 4th | Murray | 16 July 1902 | William George | Opposition | William Atkins | Independent | 1 July 1902 | Resignation | No |
| 4th | West Perth | 14 July 1902 | George Leake | Opposition | Charles Moran | Independent | 24 June 1902 | Resignation | No |
| 4th | Claremont | 11 June 1902 | William Sayer | Ministerial | John Foulkes | Opposition | 28 May 1902 | Resignation | No |
| 4th | North Perth | 5 October 1901 | Richard Speight | Opposition | George McWilliams | Opposition | 19 September 1901 | Resignation | Yes |
| 4th | West Kimberley | 23 July 1901 | Alexander Forrest | Ministerial | Sydney Pigott | Ministerial | 20 June 1901 | Death | Yes |
| 3rd | Albany | 24 July 1900 | George Leake | Opposition | John Hassell | Opposition | 10 July 1900 | Resignation | Yes |
| 3rd | Geraldton | 24 July 1900 | Richard Robson | Independent | Robert Hutchinson | Opposition | 13 June 1900 | Resignation | No |
| 3rd | De Grey | 28 May 1900† | E. T. Hooley | Ministerial | Leonard Darlot | Ministerial | 1 May 1900 | Resignation (ill health) | Yes |
| 3rd | Ashburton | 24 April 1900† | Septimus Burt | Ministerial | David Forrest | Ministerial | 10 April 1900 | Resignation | Yes |
† Won by acclamation; this date is the date of the return of the writ.

### 1890–1899

| Parl. | By-election | Date | Incumbent | Party | Winner | Party | Vacated | Cause | Retained |
| 3rd | North Murchison | 18 September 1899 | Henry Kenny | Opposition | Frederick Moorhead | Ministerial | 25 August 1899 | Death | No |
| 3rd | Geraldton | 12 July 1899 | George Simpson | Opposition | Richard Robson | Independent | 27 June 1899 | Resignation | No |
| 3rd | York | 26 June 1899† | Frederick Monger | Ministerial | Frederick Monger | Ministerial | 15 June 1899 | Resignation | Yes |
| 3rd | Gascoyne | 26 June 1899† | George Hubble | Ministerial | George Hubble | Ministerial | 13 June 1899 | Resignation | Yes |
| 2nd | Fremantle | 18 July 1896 | William Marmion | | John Higham | | 4 July 1896 | Death | |
| 2nd | North Fremantle | 22 May 1895 | William Silas Pearse | | Matthew Moss | | 2 May 1895†† | Resignation | |
| 2nd | Murray | 12 January 1895 | William Paterson | | William George | | 4 January 1895 | Resignation | |
| 2nd | Murchison | 15 October 1894† | Everard Darlot | | E. T. Hooley | | 18 September 1894 | Resignation | |
| 1st | East Kimberley | 20 April 1893† | William Baker | | Francis Connor | | 7 January 1893 | Death | |
| 1st | York | 27 October 1892† | Stephen Henry Parker | | Frederick Monger | | 5 October 1892 | Resignation | |
| 1st | South Fremantle | 12 October 1892 | David Symon | | Elias Solomon | | 13 September 1892 | Resignation | |
| 1st | Moore | 11 August 1892† | George Randell | | Henry Lefroy | | 4 July 1892 | Resignation | |
| 1st | Perth | 12 January 1892 | Edward Scott | | Thomas Molloy | | 22 December 1891†† | Resignation | |
| 1st | Geraldton | 10 December 1891† | Edward Vivien Harvey Keane | | George Simpson | | 6 November 1891†† | Resignation | |
| 1st | Roebourne | 16 January 1891† | George Leake | | Horace Sholl | | 30 December 1890 | Resignation | |
† Won by acclamation; this date is the date of the return of the writ. †† This was the date which the writ was issued – the date of the event which caused the by-election is unknown.

### Ministerial by-elections

The following ministers had to resign their seats and recontest them at a ministerial by-election. Most were unopposed; these are noted in italics in the table.
| Parl. | Electorate | Date | Member | Party | Winner | Party | Appointed | Ministry | Retained |
| 19th | Murray-Wellington | 17 April 1947 | Ross McLarty | Liberal | | | 1 April 1947 | McLarty-Watts | Yes |
| 19th | Katanning | 17 April 1947 | Arthur Watts | Country | | | 1 April 1947 | McLarty-Watts | Yes |
| 19th | West Perth | 17 April 1947 | Sir Ross McDonald | Liberal | | | 1 April 1947 | McLarty-Watts | Yes |
| 19th | Toodyay | 17 April 1947 | Lindsay Thorn | Country | | | 1 April 1947 | McLarty-Watts | Yes |
| 19th | Williams-Narrogin | 17 April 1947 | Victor Doney | Country | | | 1 April 1947 | McLarty-Watts | Yes |
| 19th | North Perth | 17 April 1947 | Arthur Abbott | Liberal | | | 1 April 1947 | McLarty-Watts | Yes |
| 19th | Pingelly | 17 April 1947 | Harrie Seward | Country | | | 1 April 1947 | McLarty-Watts | Yes |
| 18th | Murchison | 17 August 1945 | William Marshall | Labor | | | 3 August 1945 | Wise | Yes |
| 18th | North-East Fremantle | 17 December 1943 | John Tonkin | Labor | | | 9 December 1943 | Willcock | Yes |
| 17th | Kanowna | 5 April 1939 | Emil Nulsen | Labor | | | 29 March 1939 | Willcock | Yes |
| 17th | Kimberley | 5 April 1939 | Aubrey Coverley | Labor | | | 29 March 1939 | Willcock | Yes |
| 16th | Leederville | 9 April 1938 | Alexander Panton | Labor | | | 24 March 1938 | Willcock | Yes |
| 16th | Brown Hill-Ivanhoe | 4 September 1936 | Frederick Smith | Labor | | | 27 August 1936 | Willcock | Yes |
| 16th | Northam | 22 May 1936 | Albert Hawke | Labor | | | 13 May 1936 | 2nd Collier | Yes |
| 15th | Gascoyne | 11 April 1935 | Frank Wise | Labor | | | 26 March 1935 | 2nd Collier | Yes |
| 15th | Boulder | 2 May 1933 | Philip Collier | Labor | | | 24 April 1933 | 2nd Collier | Yes |
| 15th | South Fremantle | 2 May 1933 | Alexander McCallum | Labor | | | 24 April 1933 | 2nd Collier | Yes |
| 15th | Geraldton | 2 May 1933 | John Willcock | Labor | | | 24 April 1933 | 2nd Collier | Yes |
| 15th | Hannans | 2 May 1933 | Selby Munsie | Labor | | | 24 April 1933 | 2nd Collier | Yes |
| 15th | Mount Magnet | 2 May 1933 | Frank Troy | Labor | | | 24 April 1933 | 2nd Collier | Yes |
| 15th | Mount Hawthorn | 2 May 1933 | Harry Millington | Labor | | | 24 April 1933 | 2nd Collier | Yes |
| 15th | East Perth | 2 May 1933 | James Kenneally | Labor | | | 24 April 1933 | 2nd Collier | Yes |
| 14th | Northam | 1 May 1930 | Sir James Mitchell | Nationalist | | | 24 April 1930 | 2nd Mitchell | Yes |
| 14th | York | 1 May 1930 | Charles Latham | Country | | | 24 April 1930 | 2nd Mitchell | Yes |
| 14th | West Perth | 1 May 1930 | Thomas Davy | Nationalist | | | 24 April 1930 | 2nd Mitchell | Yes |
| 14th | Maylands | 1 May 1930 | John Scaddan | Nationalist | | | 24 April 1930 | 2nd Mitchell | Yes |
| 14th | Mount Marshall | 1 May 1930 | John Lindsay | Country | | | 24 April 1930 | 2nd Mitchell | Yes |
| 14th | Nedlands | 1 May 1930 | Norbert Keenan | Nationalist | | | 24 April 1930 | 2nd Mitchell | Yes |
| 14th | Irwin-Moore | 1 May 1930 | Percy Ferguson | Country | | | 24 April 1930 | 2nd Mitchell | Yes |
| 13th | Leederville | 23 December 1927 | Harry Millington | Labor | | | 15 December 1927 | 1st Collier | Yes |
| 13th | Kalgoorlie | 23 December 1927 | James Cunningham | Labor | | | 15 December 1927 | 1st Collier | Yes |
| 13th | Hannans | 9 May 1927 | Selby Munsie | Labor | | | 30 April 1927 | 1st Collier | Yes |
| 12th | Boulder | 1 May 1924 | Philip Collier | Labor | | | 16 April 1924 | 1st Collier | Yes |
| 12th | North-East Fremantle | 1 May 1924 | William Angwin | Labor | | | 16 April 1924 | 1st Collier | Yes |
| 12th | Mount Magnet | 1 May 1924 | Frank Troy | Labor | | | 16 April 1924 | 1st Collier | Yes |
| 12th | Geraldton | 1 May 1924 | John Willcock | Labor | | | 16 April 1924 | 1st Collier | Yes |
| 12th | South Fremantle | 1 May 1924 | Alexander McCallum | Labor | | | 16 April 1924 | 1st Collier | Yes |
| 11th | Swan | 31 August 1922 | Richard Sampson | Country | | | 22 August 1922 | Mitchell | Yes |
| 11th | Greenough | 27 April 1921 | Henry Maley | Country | | | 13 April 1921 | 1st Mitchell | Yes |
| 10th | Beverley | 10 July 1919 | Frank Broun | Country | | | 25 June 1919 | 1st Mitchell | Yes |
| 10th | West Perth | 7 June 1919 | Thomas Draper | Nationalist | | | 17 May 1919 | 1st Mitchell | Yes |
| 10th | Northam | 24 April 1919 | James Mitchell | Nationalist | | | 17 April 1919 | Colebatch | Yes |
| 9th | Brown Hill-Ivanhoe | 21 July 1917 | John Scaddan | National Labor | John Lutey | Labor | 28 June 1917 | Lefroy | No |
| 9th | Irwin | 11 July 1917 | James Gardiner | Nationalist | | | 28 June 1917 | Lefroy | Yes |
| 9th | Sussex | 9 August 1916 | Frank Wilson | Liberal | | | 27 July 1916 | 2nd Wilson | Yes |
| 9th | Moore | 9 August 1916 | Sir Henry Lefroy | Liberal | | | 27 July 1916 | 2nd Wilson | Yes |
| 9th | Northam | 19 August 1916 | James Mitchell | Liberal | | | 27 July 1916 | 2nd Wilson | Yes |
| 9th | Murray-Wellington | 9 August 1916 | William George | Liberal | | | 27 July 1916 | 2nd Wilson | Yes |
| 9th | Canning | 19 August 1916 | Robert Robinson | Liberal | | | 27 July 1916 | 2nd Wilson | Yes |
| 9th | North-East Fremantle | 2 December 1914 | William Angwin | Labor | | | 23 November 1914 | Scaddan | Yes |
| 8th | Brown Hill-Ivanhoe | 17 October 1911 | John Scaddan | Labor | | | 7 October 1911 | Scaddan | Yes |
| 8th | Boulder | 17 October 1911 | Philip Collier | Labor | | | 7 October 1911 | Scaddan | Yes |
| 8th | Avon | 17 October 1911 | Thomas Bath | Labor | | | 7 October 1911 | Scaddan | Yes |
| 8th | Guildford | 17 October 1911 | William Johnson | Labor | | | 7 October 1911 | Scaddan | Yes |
| 8th | Kanowna | 17 October 1911 | Thomas Walker | Labor | | | 7 October 1911 | Scaddan | Yes |
| 7th | Subiaco | 24 September 1910 | Henry Daglish | Ministerial | | | 16 September 1910 | 1st Wilson | Yes |
| 7th | Greenough | 8 July 1909 | John Nanson | Ministerial | | | 30 June 1909 | Moore | Yes |
| 7th | Northam | 3 June 1909 | James Mitchell | Ministerial | | | 14 May 1909 | Moore | Yes |
| 6th | Fremantle | 25 May 1906 | James Price | Ministerial | | | 7 May 1906 | Moore | Yes |
| 6th | Kalgoorlie | 16 May 1906 | Norbert Keenan | Ministerial | | | 7 May 1906 | Moore | Yes |
| 5th | Guildford | 14 September 1905 | Hector Rason | Ministerial | | | 25 August 1905 | Rason | Yes |
| 5th | Menzies | 14 September 1905 | Henry Gregory | Ministerial | | | 25 August 1905 | Rason | Yes |
| 5th | Sussex | 14 September 1905 | Frank Wilson | Ministerial | | | 25 August 1905 | Rason | Yes |
| 5th | Bunbury | 14 September 1905 | Newton Moore | Ministerial | | | 25 August 1905 | Rason | Yes |
| 5th | Roebourne | 13 September 1905 | John Sydney Hicks | Ministerial | | | 25 August 1905 | Rason | Yes |
| 5th | Brown Hill | 22 June 1905 | Thomas Bath | Labor | | | 7 June 1905 | Daglish | Yes |
| 5th | Mount Leonora | 30 June 1905 | Patrick Lynch | Labor | | | 7 June 1905 | Daglish | Yes |
| 5th | Subiaco | 19 August 1904 | Henry Daglish | Labor | | | 10 August 1904 | Daglish | Yes |
| 5th | Mount Margaret | 19 August 1904 | George Taylor | Labor | | | 10 August 1904 | Daglish | Yes |
| 5th | Kanowna | 19 August 1904 | Robert Hastie | Labor | | | 10 August 1904 | Daglish | Yes |
| 5th | Murchison | 19 August 1904 | John Holman | Labor | | | 10 August 1904 | Daglish | Yes |
| 5th | Kalgoorlie | 19 August 1904 | William Johnson | Labor | | | 10 August 1904 | Daglish | Yes |
| 4th | Boulder | 25 February 1903 | John Marquis Hopkins | Opposition | | | 17 February 1903 | James | Yes |
| 4th | East Perth | 8 July 1902 | Walter James | Opposition | | | 1 July 1902 | James | Yes |
| 4th | Albany | 8 July 1902 | James Gardiner | Opposition | | | 1 July 1902 | James | Yes |
| 4th | West Perth | 7 January 1902 | George Leake | Opposition | | | 23 December 1901 | 2nd Leake | Yes |
| 4th | Cue | 2 January 1902 | Frederick Illingworth | Opposition | | | 23 December 1901 | 2nd Leake | Yes |
| 4th | Pilbara | 23 January 1902 | Walter Kingsmill | Opposition | | | 23 December 1901 | 2nd Leake | Yes |
| 4th | Guildford | 7 January 1902 | Hector Rason | Opposition | | | 23 December 1901 | 2nd Leake | Yes |
| 4th | Menzies | 2 January 1902 | Henry Gregory | Opposition | | | 23 December 1901 | 2nd Leake | Yes |
| 4th | Coolgardie | 6 December 1901 | Alf Morgans | Ministerial | | | 21 November 1901 | Morgans | Yes |
| 4th | North Murchison | 10 December 1901 | Frederick Moorhead | Ministerial | John Holman | Labor | 21 November 1901 | Morgans | No |
| 4th | Toodyay | 30 November 1901 | Timothy Quinlan | Ministerial | | | 21 November 1901 | Morgans | Yes |
| 4th | Murchison | 10 December 1901 | John Nanson | Ministerial | | | 21 November 1901 | Morgans | Yes |
| 4th | Perth | 6 December 1901 | Frank Wilson | Ministerial | William Purkiss | Ministerial | 21 November 1901 | Morgans | No |
| 4th | West Perth | 12 June 1901 | George Leake | Opposition | | | 27 May 1901 | 1st Leake | Yes |
| 4th | Cue | 12 June 1901 | Frederick Illingworth | Opposition | | | 27 May 1901 | 1st Leake | Yes |
| 4th | Pilbara | 12 June 1901 | Walter Kingsmill | Opposition | | | 27 May 1901 | 1st Leake | Yes |
| 4th | East Fremantle | 12 June 1901 | Joseph Holmes | Opposition | | | 27 May 1901 | 1st Leake | Yes |
| 4th | Menzies | 12 June 1901 | Henry Gregory | Opposition | | | 27 May 1901 | 1st Leake | Yes |
| 3rd | West Perth | 22 September 1900 | Barrington Wood | Ministerial | | | 10 September 1900 | Forrest | Yes |
| 3rd | Greenough | 5 November 1897 | Richard Pennefather | Ministerial | | | 27 October 1897 | Forrest | Yes |
| 3rd | Moore | 26 May 1897 | Henry Lefroy | Ministerial | | | 12 May 1897 | Forrest | Yes |
| 2nd | Northam | 27 March 1897 | George Throssell | Ministerial | | | 13 March 1897 | Forrest | Yes |
| 2nd | Williams | 18 April 1896 | Frederick Henry Piesse | Ministerial | | | 1 April 1896 | Forrest | Yes |
| 2nd | De Grey | 21 June 1895 | Alexander Richardson | Ministerial | | | 4 December 1894 | Forrest | Yes |
| 1st | Bunbury | 8 January 1891 | John Forrest | Ministerial | | | 30 December 1890 | Forrest | Yes |
| 1st | Ashburton | 8 January 1891 | Septimus Burt | Ministerial | | | 30 December 1890 | Forrest | Yes |
| 1st | Fremantle | 8 January 1891 | William Marmion | Ministerial | | | 30 December 1890 | Forrest | Yes |
| 1st | Wellington | 8 January 1891 | Harry Venn | Ministerial | | | 30 December 1890 | Forrest | Yes |