This is a list of by-elections for the Victorian Legislative Assembly. A by-election may be held when a member's seat becomes vacant through resignation, death or some other reasons. These are referred to as casual vacancies.
Brackets around a date (D/M/Y) indicate that the candidate was unopposed when nominations closed or that, as a result of an appeal against an election result, the sitting member was replaced by the appellant. These candidates were declared "elected unopposed" with effect from the date of the closing of nominations or appeal decision, and there was no need to hold a by-election. By-elections which resulted in a change in party representation are highlighted as: Gains for the Labor Party and its splinter groups in ; for the Liberal Party and its predecessors in ; for the National Party and its predecessors in ; for the Greens in and for independents and minor parties in .
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60th Legislative Assembly (2022–2026) |- !By-election !! Incumbent !! colspan=2|Party !! Reason !! Date !! Winner !! colspan=2|Party |- ||Mulgrave |Daniel Andrews || |Labor | Resigned as Premier |18 November 2023 | | | |- ||Warrandyte |Ryan Smith || |Liberal | Resigned |26 August 2023 |Nicole Werner || |Liberal |- ||Narracan |Gary Blackwood || |Liberal | Supplementary election due to death of a candidate at the 2022 election. |28 January 2023 |Wayne Farnham || |Liberal |- |colspan=9 |
59th Legislative Assembly (2018–2022) |- |colspan=9|No by-elections held |- |colspan=9|
58th Legislative Assembly (2014–2018) |- !By-election !! Incumbent !! colspan=2|Party !! Reason !! Date !! Winner !! colspan=2|Party |- bgcolor="#C2F0C2" ||Northcote |Fiona Richardson || |Labor |Died |18 November 2017 |Lidia Thorpe || |Greens |- ||South-West Coast |Denis Napthine || |Liberal |Resigned |31 October 2015 |Roma Britnell || |Liberal |- ||Polwarth |Terry Mulder || |Liberal |Resigned |31 October 2015 |Richard Riordan || |Liberal |- ||Gippsland South |Peter Ryan || |National |Resigned |14 March 2015 |Danny O'Brien || |National |- |colspan=9 |
57th Legislative Assembly (2010–2014) |- !By-election !! Incumbent !! colspan=2|Party !! Reason !! Date !! Winner !! colspan=2|Party |- ||Lyndhurst |Tim Holding || |Labor |Resigned |27 April 2013 |Martin Pakula || |Labor |- ||Melbourne |Bronwyn Pike || |Labor |Resigned |21 July 2012 |Jennifer Kanis || |Labor |- ||Niddrie |Rob Hulls || |Labor |Resigned |24 March 2012 |Ben Carroll || |Labor |- ||Broadmeadows |John Brumby || |Labor |Resigned following election loss |19 February 2011 |Frank McGuire || |Labor |- |colspan=9 |
56th Legislative Assembly (2006–2010) |- !By-election !! Incumbent !! colspan=2|Party !! Reason !! Date !! Winner !! colspan=2|Party |- ||Altona |Lynne Kosky || |Labor |Resigned |13 February 2010 |Jill Hennessy || |Labor |- ||Kororoit |Andre Haermeyer || |Labor |Resigned |28 June 2008 |Marlene Kairouz || |Labor |- ||Williamstown |Steve Bracks || |Labor |Resigned as Premier |15 September 2007 |Wade Noonan || |Labor |- ||Albert Park |John Thwaites || |Labor |Resigned as Deputy Premier |15 September 2007 |Martin Foley || |Labor |- |colspan=9 |
55th Legislative Assembly (2002–2006) |- |colspan=9|No by-elections held |- |colspan=9|
54th Legislative Assembly (1999–2002) |- !By-election !! Incumbent !! colspan=2|Party !! Reason !! Date !! Winner !! colspan=2|Party |- bgcolor="pink" ||Benalla |Pat McNamara || |National |Resigned following election loss |13 May 2000 |Denise Allen || |Labor |- bgcolor="pink" ||Burwood |Jeff Kennett || |Liberal |Resigned following election loss |11 December 1999 |Bob Stensholt || |Labor |- bgcolor="pink" ||Frankston East |Peter McLellan || |Independent | Supplementary election due to death of the sitting member at the 1999 election. |16 October 1999 |Matt Viney || |Labor |- |colspan=9 |
53rd Legislative Assembly (1996–1999) |- !By-election !! Incumbent !! colspan=2|Party !! Reason !! Date !! Winner !! colspan=2|Party |- ||Northcote |Tony Sheehan || |Labor |Resigned |15 August 1998 |Mary Delahunty || |Labor |- bgcolor="pink" ||Mitcham |Roger Pescott || |Liberal |Resigned |13 December 1997 |Tony Robinson || |Labor |- bgcolor="#d0d0d0" ||Gippsland West |Alan Brown || |Liberal |Resigned |1 February 1997 |Susan Davies || |Independent |- |colspan=9 |
52nd Legislative Assembly (1992–1996) |- !By-election !! Incumbent !! colspan=2|Party !! Reason !! Date !! Winner !! colspan=2|Party |- ||Williamstown |Joan Kirner || |Labor |Resigned |13 August 1994 |Steve Bracks || |Labor |- ||Coburg |Tom Roper || |Labor |Resigned |14 May 1994 |Carlo Carli || |Labor |- ||Broadmeadows |Jim Kennan || |Labor |Resigned |18 September 1993 |John Brumby || |Labor |- |colspan=9 |