This is a list of by-elections for the New South Wales 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.
Fifty-sixth Legislative Assembly 2015–2019 |
| By-election | Incumbent | Party | Reason for by-election | Date of by-election | Winner of by-election | Party |
|---|
| Wagga Wagga | Daryl Maguire | Liberal}}| | Liberal | Resigned | 8 September 2018 | Joe McGirr | Independent}}| | Independent |
| Blacktown | John Robertson | Labor}}| | Labor | Resigned | 14 October 2017 | Stephen Bali | Labor}}| | Labor |
| Cootamundra | Katrina Hodgkinson | Nationals}}| | National | Resigned | 14 October 2017 | Steph Cooke | Nationals}}| | National |
| Murray | Adrian Piccoli | Nationals}}| | National | Resigned | 14 October 2017 | Austin Evans | Nationals}}| | National |
| Gosford | Kathy Smith | Labor}}| | Labor | Resigned due to ill health | 8 April 2017 | Liesl Tesch | Labor}}| | Labor |
| Manly | Mike Baird | Liberal}}| | Liberal | Resigned | 8 April 2017 | James Griffin | Liberal}}| | Liberal |
| North Shore | Jillian Skinner | Liberal}}| | Liberal | Resigned | 8 April 2017 | Felicity Wilson | Liberal}}| | Liberal |
| Canterbury | Linda Burney | Labor}}| | Labor | Resigned to contest federal seat of Barton | 12 November 2016 | Sophie Cotsis | Labor}}| | Labor |
| Orange | Andrew Gee | Nationals}}| | National | Resigned to contest federal seat of Calare | 12 November 2016 | Philip Donato | Shooters}}| | SFF |
| Wollongong | Noreen Hay | Labor}}| | Labor | Resigned | 12 November 2016 | Paul Scully | Labor}}| | Labor |
Fifty-fifth Legislative Assembly 2011–2015 |
| By-election | Incumbent | Party | Reason for by-election | Date of by-election | Winner of By-election | Party |
|---|
|
| Charlestown | Andrew Cornwell | Liberal}}| | Liberal | Resigned due to ICAC investigation | 25 October 2014 | Jodie Harrison | Labor}}| | Labor |
| Newcastle | Tim Owen | Liberal}}| | Liberal | Resigned due to ICAC investigation | 25 October 2014 | Tim Crakanthorp | Labor}}| | Labor |
| Miranda | Graham Annesley | Liberal}}| | Liberal | Resigned to become CEO of Gold Coast Titans rugby league team | 19 October 2013 | Barry Collier | Labor}}| | Labor |
| Northern Tablelands | Richard Torbay | Independent}}| | Independent | Resigned | 25 May 2013 | Adam Marshall | National}}| | National |
| Sydney | Clover Moore | Independent}}| | Independent | Resigned due to new state laws preventing dual membership of state parliament and local council | 27 October 2012 | Alex Greenwich | Independent}}| | Independent |
| Heffron | Kristina Keneally | Labor}}| | Labor | Resigned after being appointed CEO of Basketball Australia | 25 August 2012 | Ron Hoenig | Labor}}| | Labor |
| Clarence | Steve Cansdell | Nationals}}| | National | Resigned after falsifying a statutory declaration regarding a speeding offence | 19 November 2011 | Chris Gulaptis | Nationals}}| | National |
Fifty-fourth Legislative Assembly 2007–2011 |
| By-election | Incumbent | Party | Reason for by-election | Date of by-election | Winner of By-election | Party |
|---|
|
| Penrith | Karyn Paluzzano | Labor}}| | Labor | Resigned after misleading ICAC | 19 June 2010 | Stuart Ayres | Liberal}}| | Liberal |
| Cabramatta | Reba Meagher | Labor}}| | Labor | Resigned after being dismissed from cabinet | 18 October 2008 | Nick Lalich | Labor}}| | Labor |
| Lakemba | Morris Iemma | Labor}}| | Labor | Resigned after losing confidence of caucus | 18 October 2008 | Robert Furolo | Labor}}| | Labor |
| Port Macquarie | Rob Oakeshott | Independent}}| | Independent | Resigned to contest federal Lyne by-election | 18 October 2008 | Peter Besseling | Independent}}| | Independent |
| Ryde | John Watkins | Labor}}| | Labor | Resigned to spend time with family | 18 October 2008 | Victor Dominello | Liberal}}| | Liberal |
Fifty-third Legislative Assembly 2003–2007 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Dubbo | Tony McGrane | Independent}}| | Independent | Death | 20 November 2004 | Dawn Fardell | Independent}}| | Independent |
| Maroubra | Bob Carr | Labor}}| | Labor | Resigned as Premier | 17 September 2005 | Michael Daley | Labor}}| | Labor |
| Marrickville | Andrew Refshauge | Labor}}| | Labor | Resigned as Deputy Premier | 17 September 2005 | Carmel Tebbutt | Labor}}| | Labor |
| Macquarie Fields | Craig Knowles | Labor}}| | Labor | Resigned after it became apparent that he would not become Premier | 17 September 2005 | Steven Chaytor | Labor}}| | Labor |
| Pittwater | John Brogden | Liberal}}| | Liberal | Ill health | 26 November 2005 | Alex McTaggart | Independent}}| | Independent |
Fifty-second Legislative Assembly 1999–2003 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Campbelltown | Michael Knight | Labor}}| | Labor | Resigned after completion of term as Olympics Minister | 3 February 2001 | Graham West | Labor}}| | Labor |
| Auburn | Peter Nagle | Labor}}| | Labor | Ill health | 8 September 2001 | Barbara Perry | Labor}}| | Labor |
| Tamworth | Tony Windsor | Independent}}| | Independent | Resigned to contest federal seat of New England at 2001 election | 8 December 2001 | John Cull | Nationals}}| | National |
| Hornsby | Stephen O'Doherty | Liberal}}| | Liberal | Resigned | 23 February 2002 | Judy Hopwood | Liberal}}| | Liberal |
Fifty-first Legislative Assembly 1995–1999 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Clarence | Ian Causley | Nationals}}| | National | Resigned to contest federal seat of Page at the 1996 election | 25 May 1996 | Harry Woods | Labor}}| | Labor |
| Southern Highlands | John Fahey | Liberal}}| | Liberal | Resigned to contest federal seat of Macarthur at the 1996 election | 25 May 1996 | Peta Seaton | Liberal}}| | Liberal |
| Strathfield | Paul Zammit | Liberal}}| | Liberal | Resigned to contest federal seat of Lowe at the 1996 election | 25 May 1996 | Bruce MacCarthy | Liberal}}| | Liberal |
| Orange | Garry West | Nationals}}| | National | Resigned | 25 May 1996 | Russell Turner | Nationals}}| | National |
| Pittwater | Jim Longley | Liberal}}| | Liberal | Resigned | 25 May 1996 | John Brogden | Liberal}}| | Liberal |
| Port Macquarie | Wendy Machin | Nationals}}| | National | Resigned | 30 November 1996 | Rob Oakeshott | Nationals}}| | National |
| Sutherland | Chris Downy | Liberal}}| | Liberal | Resigned | 12 February 1997 | Lorna Stone | Liberal}}| | Liberal |
Fiftieth Legislative Assembly 1991–1995 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| The Entrance | Bob Graham | Liberal}}| | Liberal | Result overturned by the Court of Disputed Returns | 18 January 1992 | Grant McBride | Labor}}| | Labor |
| Davidson | Terry Metherell | Independent}}| | Independent | Accepted an appointment in the public service (see Metherell affair) | 2 May 1992 | Andrew Humpherson | Liberal}}| | Liberal |
| Ku-ring-gai | Nick Greiner | Liberal}}| | Liberal | Resigned after losing Premiership (see Metherell affair) | 22 August 1992 | Stephen O'Doherty | Liberal}}| | Liberal |
| Gordon | Tim Moore | Liberal}}| | Liberal | Resigned (see Metherell affair) | 22 August 1992 | Jeremy Kinross | Liberal}}| | Liberal |
| The Hills | Tony Packard | Liberal}}| | Liberal | Resigned after involvement in a business scandal | 28 August 1993 | Michael Richardson | Liberal}}| | Liberal |
| North Shore | Phillip Smiles | Liberal}}| | Liberal | Resigned | 5 February 1994 | Jillian Skinner | Liberal}}| | Liberal |
| Vaucluse | Michael Yabsley | Liberal}}| | Liberal | Resigned | 9 April 1994 | Peter Debnam | Liberal}}| | Liberal |
| Parramatta | Andrew Ziolkowski | Labor}}| | Labor | Death | 27 August 1994 | Gabrielle Harrison | Labor}}| | Labor |
| Cabramatta | John Newman | Labor}}| | Labor | Assassinated by Phuong Ngo | 22 October 1994 | Reba Meagher | Labor}}| | Labor |
Forty-ninth Legislative Assembly 1988–1991 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Vaucluse | Ray Aston | Liberal}}| | Liberal | Death | (6 June 1988)* | Michael Yabsley | Liberal}}| | Liberal |
| North Shore | Ted Mack | Independent}}| | Independent | Resigned | 5 November 1988 | Robyn Read | Independent}}| | Independent |
| Port Stephens | Bob Martin | Labor}}| | Labor | Result voided by the Court of Disputed Returns | 5 November 1988 | Bob Martin | Labor}}| | Labor |
| Wallsend | Ken Booth | Labor}}| | Labor | Death | 17 December 1988 | John Mills | Labor}}| | Labor |
| Liverpool | George Paciullo | Labor}}| | Labor | Resigned after being passed over as leader of the party | 29 April 1989 | Peter Anderson | Labor}}| | Labor |
| Heffron | Laurie Brereton | Labor}}| | Labor | Successfully contested the federal seat of Kingsford-Smith at the 1990 election | 23 June 1990 | Deirdre Grusovin | Labor}}| | Labor |
| Smithfield | Janice Crosio | Labor}}| | Labor | Successfully contested the federal seat of Prospect at the 1990 election | 23 June 1990 | Carl Scully | Labor}}| | Labor |
| Granville | Laurie Ferguson | Labor}}| | Labor | Successfully contested the federal seat of Reid at the 1990 election | 23 June 1990 | Kim Yeadon | Labor}}| | Labor |
| The Hills | Fred Caterson | Liberal}}| | Liberal | Resigned | 1 September 1990 | Tony Packard | Liberal}}| | Liberal |
| Coffs Harbour | Matt Singleton | Nationals}}| | National | Resigned | 3 November 1990 | Andrew Fraser | Nationals}}| | National |
| Macquarie Fields | Stan Knowles | Labor}}| | Labor | Resigned | 3 November 1990 | Craig Knowles | Labor}}| | Labor |
- Although the Vaucluse by-election was set for 18 June 1988, Michael Yabsley was declared elected unopposed on the close of nominations on 6 June.
Forty-eighth Legislative Assembly 1984–1988 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Murray | Tim Fischer | Nationals}}| | National | Successfully contested the seat of Farrer at the 1984 federal election | 2 February 1985 | Jim Small | Nationals}}| | National |
| Peats | Paul Landa | Labor}}| | Labor | Death | 2 February 1985 | Tony Doyle | Labor}}| | Labor |
| Gloucester | Leon Punch | Nationals}}| | National | Resigned | 12 October 1985 | Wendy Machin | Nationals}}| | National |
| Cabramatta | Eric Bedford | Labor}}| | Labor | Resigned | 1 February 1986 | John Newman | Labor}}| | Labor |
| Canterbury | Kevin Stewart | Labor}}| | Labor | Accepted position as Agent-General in London | 1 February 1986 | Kevin Moss | Labor}}| | Labor |
| Kiama | Bill Knott | Labor}}| | Labor | Resigned | 1 February 1986 | Bob Harrison | Labor}}| | Labor |
| Vaucluse | Rosemary Foot | Liberal}}| | Liberal | Resigned | 31 May 1986 | Ray Aston | Liberal}}| | Liberal |
| Pittwater | Max Smith | Independent}}| | Independent | Resigned | 31 May 1986 | Jim Longley | Liberal}}| | Liberal |
| Bass Hill | Neville Wran | Labor}}| | Labor | Resigned | 2 August 1986 | Michael Owen | Liberal}}| | Liberal |
| Rockdale | Brian Bannon | Labor}}| | Labor | Accepted a government position and created a seat for the Premier | 2 August 1986 | Barrie Unsworth | Labor}}| | Labor |
| Heathcote | Rex Jackson | Labor}}| | Labor | Resigned amidst a corruption scandal that ultimately led to his imprisonment | 31 January 1987 | Ian McManus | Labor}}| | Labor |
| Bankstown | Ric Mochalski | Labor}}| | Labor | Resigned after being charged with fraud | 31 January 1987 | Doug Shedden | Labor}}| | Labor |
| Northern Tablelands | Bill McCarthy | Labor}}| | Labor | Death | 23 May 1987 | Ray Chappell | Nationals}}| | National |
Forty-seventh Legislative Assembly 1981–1984 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Drummoyne | Michael Maher | Labor}}| | Labor | Successfully contested the federal seat of Lowe at the Lowe by-election, 1982 | 17 April 1982 | John Murray | Labor}}| | Labor |
| Marrickville | Tom Cahill | Labor}}| | Labor | Death | 22 October 1983 | Andrew Refshauge | Labor}}| | Labor |
| Riverstone | Tony Johnson | Labor}}| | Labor | Resigned | 22 October 1983 | Richard Amery | Labor}}| | Labor |
| Kogarah | Bill Crabtree | Labor}}| | Labor | Resigned after losing cabinet position | 22 October 1983 | Brian Langton | Labor}}| | Labor |
| Maroubra | Bill Haigh | Labor}}| | Labor | Resigned after losing cabinet position | 22 October 1983 | Bob Carr | Labor}}| | Labor |
Forty-sixth Legislative Assembly 1978–1981 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Castlereagh | Jack Renshaw | Labor}}| | Labor | Resigned | 23 February 1980 | Jim Curran | Labor}}| | Labor |
| Murray | Mary Meillon | Liberal}}| | Liberal | Death | 13 September 1980 | Tim Fischer | Nationals}}| | National Country |
| Ku-ring-gai | John Maddison | Liberal}}| | Liberal | Resigned | 13 September 1980 | Nick Greiner | Liberal}}| | Liberal |
| Bankstown | Nick Kearns | Labor}}| | Labor | Death | 13 September 1980 | Ric Mochalski | Labor}}| | Labor |
| Sturt | Tim Fischer | Nationals}}| | National Country | Successfully contested the federal seat of Farrer at the 1980 election | 21 February 1981 | John Sullivan | Nationals}}| | National Country |
| Cessnock | Bob Brown | Labor}}| | Labor | Successfully contested the federal seat of Hunter at the 1980 election | 21 February 1981 | Stan Neilly | Labor}}| | Labor |
| Oxley | Bruce Cowan | Nationals}}| | National Country | Successfully contested the federal seat of Lyne at the 1980 election | 21 February 1981 | Peter King | Nationals}}| | National Country |
| Maitland | Milton Morris | Liberal}}| | Liberal | Unsuccessfully contested the federal seat of Lyne at the 1980 election | 21 February 1981 | Peter Toms | Liberal}}| | Liberal |
Forty-fifth Legislative Assembly 1976–1978 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| The Hills | Max Ruddock | Liberal}}| | Liberal | Resigned | 9 October 1976 | Fred Caterson | Liberal}}| | Liberal |
| Earlwood | Eric Willis | Liberal}}| | Liberal | Resigned | 15 July 1978 | Ken Gabb | Labor}}| | Labor |
Forty-fourth Legislative Assembly 1973–1976 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Goulburn | Ron Brewer | Nationals}}| | National Country | Unsuccessfully contested the federal seat of Eden-Monaro at the 1974 federal election | 20 July 1974 | Ron Brewer | Nationals}}| | National Country |
| Coogee | Ross Freeman | Liberal}}| | Liberal | Result voided by the Court of Disputed Returns | 20 July 1974 | Michael Cleary | Labor}}| | Labor |
| Pittwater | Robert Askin | Liberal}}| | Liberal | Resigned | 8 February 1975 | Bruce Webster | Liberal}}| | Liberal |
| Lane Cove | Ken McCaw | Liberal}}| | Liberal | Resigned | 8 February 1975 | John Dowd | Liberal}}| | Liberal |
| Wagga Wagga | Wal Fife | Liberal}}| | Liberal | Successfully contested the seat of Farrer at the 1975 federal election | 6 December 1975 | Joe Schipp | Liberal}}| | Liberal |
| Orange | Charles Cutler | Nationals}}| | National Country | Resigned | 14 February 1976 | Garry West | Nationals}}| | National Country |
Forty-third Legislative Assembly 1971–1973 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Mosman | Pat Morton | Liberal}}| | Liberal | Resigned | 29 July 1972 | David Arblaster | Liberal}}| | Liberal |
| Charlestown | Jack Stewart | Labor}}| | Labor | Death | 18 November 1972. | Richard Face | Labor}}| | Labor |
| Hawkesbury | Bernie Deane | Liberal}}| | Liberal | Resigned | 17 February 1973 | Kevin Rozzoli | Liberal}}| | Liberal |
| Armidale | Davis Hughes | Nationals}}| | Country | Accepted position as Agent-General in London | 17 February 1973 | David Leitch | Nationals}}| | Country |
| Byron | Stanley Stephens | Nationals}}| | Country | Resigned | 17 February 1973 | Jack Boyd | Nationals}}| | Country |
| Murray | Joe Lawson | Independent}}| | Independent | Death | 6 October 1973 | Mary Meillon | Liberal}}| | Liberal |
Forty-second Legislative Assembly 1968–1971 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Lake Macquarie | Jim Simpson | Labor}}| | Labor | Death | 9 April 1969 | Merv Hunter | Labor}}| | Labor |
| Upper Hunter | Frank O'Keefe | Nationals}}| | Country | Successfully contested the federal seat of Paterson at the 1969 federal election | 14 February 1970 | Col Fisher | Nationals}}| | Country |
| Randwick | Lionel Bowen | Labor}}| | Labor | Successfully contested the federal seat of Kingsford Smith at the 1969 federal election | 14 February 1970 | Laurie Brereton | Labor}}| | Labor |
| Murrumbidgee | Al Grassby | Labor}}| | Labor | Successfully contested the federal seat of Riverina at the 1969 federal election | 14 February 1970 | Lin Gordon | Labor}}| | Labor |
| Georges River | Douglas Cross | Liberal}}| | Liberal | Death | 19 September | Frank Walker | Labor}}| | Labor |
Forty-first Legislative Assembly 1965–1968 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Bondi | Abe Landa | Labor}}| | Labor | Accepted the position of state Agent-General in London | 6 November 1965 | Syd Einfeld | Labor}}| | Labor |
| Oxley | Les Jordan | Liberal}}| | Liberal | Death | 6 November 1965 | Bruce Cowan | Nationals}}| | Country |
| Bathurst | Gus Kelly | Labor}}| | Labor | Death | 6 May 1967 | Clive Osborne | Nationals}}| | Country |
Fortieth Legislative Assembly 1962–1965 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Casino | Ian Robinson | Nationals}}| | Country | Successfully contested the federal seat of Cowper at the 1963 election | 29 February 1964 | Richmond Manyweathers | Nationals}}| | Country |
| Wollongong-Kembla | Rex Connor | Labor}}| | Labor | Successfully contested the federal seat of Cunningham at the 1963 election | 29 February 1964 | Doug Porter | Labor}}| | Labor |
| Waratah | Edward Greaves | Labor}}| | Labor | Death | 8 August 1964 | Frank Purdue | Independent}}| | Independent |
| Lakemba | Stan Wyatt | Labor}}| | Labor | Death | 19 September 1964 | Vince Durick | Labor}}| | Labor |
Thirty-ninth Legislative Assembly 1959–1962 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Lismore | Jack Easter | Nationals}}| | Country | Result voided by the Court of Disputed Returns | 12 September 1959. | Keith Compton | Labor}}| | Labor |
| Cook's River | Joseph Cahill | Labor}}| | Labor | Death | 12 December 1959 | Tom Cahill | Labor}}| | Labor |
| Kurri Kurri | George Booth | Labor}}| | Labor | Death | 8 October 1960 | Ken Booth | Labor}}| | Labor |
| Temora | Doug Dickson | Nationals}}| | Country | Death | 8 October 1960 | Jim Taylor | Nationals}}| | Country |
| Paddington-Waverley | William Ferguson | Labor}}| | Labor | Death | 25 February 1961 | Keith Anderson | Labor}}| | Labor |
| Liverpool Plains | Roger Nott | Labor}}| | Labor | Accepted an appointment as Administrator of the Northern Territory | 25 March 1961 | Frank O'Keefe | Nationals}}| | Country |
Thirty-eighth Legislative Assembly 1956–1959 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Burwood | Leslie Parr | Liberal}}| | Liberal | Death | 16 February 1957 | Ben Doig | Liberal}}| | Liberal |
| Kahibah | Tom Armstrong | Independent}}| | Independent Labor | Death | 13 April 1957 | Jack Stewart | Labor}}| | Labor |
| Vaucluse | Murray Robson | Liberal}}| | Liberal | Resigned | 24 August 1957 | Geoffrey Cox | Liberal}}| | Liberal |
| Wollondilly | Blake Pelly | Liberal}}| | Liberal | Resigned | 26 October 1957 | Tom Lewis | Liberal}}| | Liberal |
| Wagga Wagga | Eddie Graham | Labor}}| | Labor | Death | 14 December 1957 | Wal Fife | Liberal}}| | Liberal |
Thirty-seventh Legislative Assembly 1953–1956 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Dulwich Hill | George Weir | Labor}}| | Labor | Appointed to the Industrial Relations Commission of New South Wales | 20 June 1953 | Cliff Mallam | Labor}}| | Labor |
| Waverley | Clarrie Martin | Labor}}| | Labor | Death | 31 October 1953 | William Ferguson | Labor}}| | Labor |
| Kahibah | Joshua Arthur | Labor}}| | Labor | Resigned after being expelled from the Labor Party, following adverse findings into his conduct by a Royal Commission | 31 October 1953 | Tom Armstrong | Independent}}| | Independent Labor |
| Leichhardt | Claude Matthews | Labor}}| | Labor | Committed suicide | 20 March 1954 | Reg Coady | Labor}}| | Labor |
| Phillip | Tom Shannon | Labor}}| | Labor | Death | 14 August 1954 | Pat Hills | Labor}}| | Labor |
| Clarence | Cecil Wingfield | Nationals}}| | Country | Death | 26 March 1955 | Bill Weiley | Nationals}}| | Country |
| Bulli | Laurie Kelly Sr. | Labor}}| | Labor | Death | 9 July 1955 | Rex Jackson | Labor}}| | Labor |
Thirty-sixth Legislative Assembly 1950–1953 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Burwood | Gordon Jackett | Liberal}}| | Liberal | Death | 2 June 1951 | Leslie Parr | Liberal}}| | Liberal |
| Neutral Bay | Ivan Black | Liberal}}| | Liberal | Unsuccessfully contested preselection for the federal seat of Warringah at the 1951 election | (21 May 1951) | Ivan Black | Liberal}}| | Liberal |
| Liverpool | James McGirr | Labor}}| | Labor | Appointed chair of the Maritime Services Board | 24 May 1952 | Jack Mannix | Labor}}| | Labor |
| Ashfield | Athol Richardson | Liberal}}| | Liberal | Appointed to the Supreme Court of New South Wales | 28 June 1952 | Jack Richardson | Labor}}| | Labor |
Thirty-fifth Legislative Assembly 1947–1950 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Hartley | Hamilton Knight | Labor}}| | Labor | Accepted an appointment to the Commonwealth Industrial Commission | 13 December 1947 | Jim Chalmers | Labor}}| | Labor |
| Coogee | Lou Cunningham | Labor}}| | Labor | Death | 8 May 1948 | Kevin Ellis | Liberal}}| | Liberal |
| Kogarah | William Currey | Labor}}| | Labor | Death | 17 July 1948 | Douglas Cross | Liberal}}| | Liberal |
| Cobar | Mat Davidson | Labor}}| | Labor | Death | 12 March 1949 | Ernest Wetherell | Labor}}| | Labor |
| Concord | Bill Carlton | Labor}}| | Labor | Death | 12 March 1949 | Brice Mutton | Liberal}}| | Liberal |
| Redfern | George Noble | Labor}}| | Labor | Death | 8 October 1949 | Kevin Dwyer | Labor}}| | Labor |
| Cessnock | Jack Baddeley | Labor}}| | Labor | Accepted an appointment as Chairman of the State Coal Mine Authority | 8 October 1949 | John Crook | Labor}}| | Labor |
| Wollondilly | Jeff Bate | Liberal}}| | Liberal | Successfully contested the seat of Macarthur at the 1949 federal election | (23 January 1950) | Blake Pelly | Liberal}}| | Liberal |
| Armidale | David Drummond | Nationals}}| | Country | Successfully contested the seat of New England at the 1949 federal election | 11 February 1950 | Davis Hughes | Nationals}}| | Country |
| Wollongong-Kembla | Billy Davies | Labor}}| | Labor | Successfully contested the seat of Cunningham at the 1949 federal election | 11 February 1950 | Baden Powell | Labor}}| | Labor |
| Concord | Brice Mutton | Liberal}}| | Liberal | Death | 11 February 1950 | John Adamson | Liberal}}| | Liberal |
Thirty-fourth Legislative Assembly 1944–1947 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Ryde | James Shand | Independent}}| | Independent Democrat | Death | 3 February 1945 | Eric Hearnshaw | Liberal}}| | Liberal |
| Blacktown | Frank Hill | Labor}}| | Labor | Death | 18 August 1945 | John Freeman | Labor}}| | Labor |
| Manly | Alfred Reid | Liberal}}| | Liberal | Death | 15 September 1945 | Douglas Darby | Liberal}}| | Liberal |
| Neutral Bay | Reginald Weaver | Liberal}}| | Liberal | Death | 15 December 1945 | Ivan Black | Liberal}}| | Liberal |
| Goulburn | Jack Tully | Labor}}| | Labor | Resigned | 1 June 1946 | Laurie Tully | Labor}}| | Labor |
| Albury | Alexander Mair | Liberal}}| | Liberal | Unsuccessfully contested a seat in the Australian Senate at the 1946 federal election | 9 November 1946 | John Hurley | Labor}}| | Labor |
| Auburn | Jack Lang | Lang Labor}}| | Lang Labor | Successfully contested the federal seat of Reid at the 1946 federal election | 9 November 1946 | James Lang | Lang Labor}}| | Lang Labor |
| Ashfield | Athol Richardson | Liberal}}| | Liberal | Unsuccessfully contested the federal seat of Parkes at the 1946 federal election | 9 November 1946 | Athol Richardson | Liberal}}| | Liberal |
| Corowa | Christopher Lethbridge | Liberal}}| | Liberal | Unsuccessfully contested the federal seat of Riverina at the 1946 federal election | 9 November 1946 | Ebenezer Kendell | Nationals}}| | Country |
Thirty-third Legislative Assembly 1941–1944 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Dubbo | George Wilson | Nationals}}| | Country | Death | 6 June 1942 | Clarrie Robertson | Labor}}| | Labor |
| South Coast | Rupert Beale | Independent}}| | Independent | Death | 14 November 1942 | Jack Beale | Independent}}| | Independent |
| Willoughby | Edward Sanders | UAP}}| | UAP | Death | 25 September 1943 | George Brain | UAP}}| | UAP |
| Lachlan | Griffith Evans | Nationals}}| | Country | Death | 25 September 1943 | John Chanter | Labor}}| | Labor |
| Auburn | Jack Lang | Lang Labor}}| | Lang Labor | Unsuccessfully contested the federal seat of Reid at the 1943 election | 2 October 1943 | Jack Lang | Lang Labor}}| | Lang Labor |
Thirty-second Legislative Assembly 1938–1941 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Coogee | John Dunningham | UAP}}| | UAP | Death | 25 June 1938 | Thomas Mutch | UAP}}| | UAP |
| Gordon | Harry Turner | UAP}}| | UAP | Result voided by Court of Disputed Returns | 24 September 1938 | Harry Turner | UAP}}| | UAP |
| Wollondilly | Mark Morton | UAP}}| | UAP | Death | 12 November 1938 | Jeff Bate | UAP}}| | UAP |
| Balmain | John Quirk | Labor}}| | Labor | Death | 14 January 1939 | Mary Quirk | Labor}}| | Labor |
| Hurstville | James Webb | UAP}}| | UAP | Death | 18 March 1939 | Clive Evatt | Industrial Labor}}| | Industrial Labor |
| Waverley | John Waddell | UAP}}| | UAP | Death | 22 April 1939 | Clarrie Martin | Industrial Labor}}| | Industrial Labor |
| Upper Hunter | Malcolm Brown | Nationals}}| | Country | Death | 7 October 1939 | D'Arcy Rose | Nationals}}| | Country |
| Tamworth | Frank Chaffey | UAP}}| | UAP | Death | 10 August 1940 | Bill Chaffey | UAP}}| | UAP |
| Croydon | Bertram Stevens | UAP}}| | UAP | Unsuccessfully contested the federal seat of Lang at the 1940 election | 7 September 1940 | David Hunter | UAP}}| | UAP |
| Ryde | Eric Spooner | UAP}}| | UAP | Successfully contested the federal seat of Robertson at the 1940 election | 14 September 1940 | Arthur Williams | Labor}}| | Labor |
| Barwon | Ben Wade | Nationals}}| | Country | Unsuccessfully contest the federal seat of Gwydir at the 1940 election | 25 October 1940 | Roy Heferen | Labor}}| | Labor |
Thirty-first Legislative Assembly 1935–1938 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Gordon | Thomas Bavin | UAP}}| | UAP | Accepted an appointment as a judge of the Supreme Court of New South Wales | (23 November 1935) | Philip Goldfinch | UAP}}| | UAP |
| Vaucluse | William Foster | UAP}}| | UAP | Death | 29 August 1936 | Murray Robson | Independent}}| | Independent UAP |
| Woollahra | Daniel Levy | UAP}}| | UAP | Death | 26 June 1937 | Harold Mason | Independent}}| | Independent UAP |
| Gordon | Philip Goldfinch | UAP}}| | UAP | Resigned (Increased commitment to business interests) | 7 August 1937 | Harry Turner | UAP}}| | UAP |
| Corowa | Richard Ball | Nationals}}| | Country | Death | 11 December 1937 | Christopher Lethbridge | Independent}}| | Independent |
Thirtieth Legislative Assembly 1932–1935 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Leichhardt | Barney Olde | Labor (NSW)}}| | Labor (NSW) | Death | 10 December 1932 | Joe Lamaro | Labor (NSW)}}| | Labor (NSW) |
| Lismore | William Missingham | Nationals}}| | Country | Death | 11 March 1933 | William Frith | Nationals}}| | Country |
| Bulli | Andrew Lysaght, junior | Labor (NSW)}}| | Labor (NSW) | Death | 3 June 1933 | John Sweeney | Labor (NSW)}}| | Labor (NSW) |
| Annandale | Robert Stuart-Robertson | Labor (NSW)}}| | Labor (NSW) | Death | 24 June 1933 | Bob Gorman | Labor (NSW)}}| | Labor (NSW) |
| Hamilton | Hugh Connell | Labor (NSW)}}| | Labor (NSW) | Death | 24 February 1934 | William Brennan | Labor (NSW)}}| | Labor (NSW) |
| Gloucester | Walter Bennett | UAP}}| | UAP | Death | 25 August 1934 | Charles Bennett | UAP}}| | UAP |
| Leichhardt | Joe Lamaro | Labor (NSW)}}| | Labor (NSW) | Unsuccessfully contested the federal seat of Watson at the 1934 election | 20 October 1934 | Claude Matthews | Labor (NSW)}}| | Labor (NSW) |
Twenty-ninth Legislative Assembly 1930–1932 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Clarence | Alfred Pollack | Nationals}}| | Country | Death | 7 March 1931 | Alfred Henry | Nationals}}| | Country |
| Annandale | Robert Stuart-Robertson | Labor (NSW)}}| | Labor (NSW) | Insolvency | 25 April 1931 | Robert Stuart-Robertson | Labor (NSW)}}| | Labor (NSW) |
| Upper Hunter | William Cameron | Nationalist}}| | Nationalist | Death | 13 June 1931 | Malcolm Brown | Nationals}}| | Country |
Twenty-eighth Legislative Assembly 1927–1930 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Wollondilly | George Fuller | Nationalist}}| | Nationalist | Accepted position as Agent-General in London in February 1928 | 3 March 1928 | Mark Morton | Nationalist}}| | Nationalist |
| Hamilton | David Murray | Labor}}| | Labor | Death | 8 September 1928 | James Smith | Labor}}| | Labor |
| Coogee | Hyman Goldstein | Nationalist}}| | Nationalist | Death – probably murdered by ex-MLA Tom Ley | 22 September 1928 | John Dunningham | Nationalist}}| | Nationalist |
| Parramatta | Albert Bruntnell | Nationalist}}| | Nationalist | Death | 23 February 1929 | Herbert Lloyd | Nationalist}}| | Nationalist |
| Ashfield | Milton Jarvie | Nationalist}}| | Nationalist | Resigned after being implicated in a bribery scandal | 5 October 1929 | Milton Jarvie | Nationalist}}| | Nationalist |
| Lane Cove | Bryce Walmsley | Nationalist}}| | Nationalist | Death | 26 July 1930 | Herbert FitzSimons | Nationalist}}| | Nationalist |
Twenty-seventh Legislative Assembly 1925–1927The 25th, 26th and 27th Legislative Assemblies were elected using a form of proportional representation with multi-member seats and a single transferable vote (modified Hare-Clark). Under the provisions of the Parliamentary Elections (Casual Vacancies) Act, casual vacancies were filled by the next unsuccessful candidate on the incumbent member's party list. If an Independent member retired, the Clerk of the Assembly determined who would fill the vacancy based on the departing members voting record in questions of confidence. The date listed as the by-election date is the day on which the new member was sworn into the Assembly. |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Sydney | John Birt | Labor}}| | Labor | Death | (24 June 1925) | Patrick Minahan | Labor}}| | Labor |
| St George | Thomas Ley | Nationalist}}| | Nationalist | Resigned to successfully contest the federal seat of Barton at the 1925 election | (30 September 1925) | William Bagnall | Nationalist}}| | Nationalist |
| Goulburn | John Perkins | Nationalist}}| | Nationalist | Resigned to successfully contest the federal seat of Eden-Monaro at the 1926 Eden-Monaro by-election. | (21 January 1926) | Henry Bate | Nationalist}}| | Nationalist |
| Cumberland | William FitzSimons | Nationalist}}| | Nationalist | Death | (22 September 1926) | James Shand | Nationalist}}| | Nationalist |
| North Shore | Alick Kay ¶ | Independent}}| | Independent | Accepted a position on the Metropolitan Meat Board. | (22 September 1926) | Arthur Tonge | Labor}}| | Labor |
¶ Kay had supported the Lang Government in votes of confidence in the Assembly, the Clerk of the Parliament therefore named the first unsuccessful Labor candidate in the North Shore electrorate as his replacement. Twenty-sixth Legislative Assembly 1922–1925 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Wammerawa | William Ashford | Independent}}| | Independent | Result overturned (Change of member without by-election) | (1 August 1922) | Joseph Clark | Labor}}| | Labor |
| Stuart | Jabez Wright | Labor}}| | Labor | Death | (30 September 1922) | Ted Horsington | Labor}}| | Labor |
| Namoi | Patrick Scully | Labor}}| | Labor | Resigned | (20 September 1923) | William Scully | Labor}}| | Labor |
| North Shore | Arthur Cocks | Nationalist}}| | Nationalist | Accepted position of Agent-General in London | (24 March 1925) | Alfred Reid | Nationalist}}| | Nationalist |
Twenty-fifth Legislative Assembly 1920–1922 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Eastern Suburbs | James Fingleton | Labor}}| | Labor | Death | (15 December 1920) | Daniel Dwyer | Labor}}| | Labor |
| Goulburn | Augustus James | Nationalist}}| | Nationalist | Accepted an appointment as a judge of the Supreme Court. | (15 December 1920) | William Millard | Nationalist}}| | Nationalist |
| Murray | George Beeby | Progressive (1920)}}| | Progressive | Accepted a judicial appointment | (15 December 1920) | Matthew Kilpatrick | Progressive (1920)}}| | Progressive |
| Oxley | George Briner | Progressive (1920)}}| | Progressive | Death | (15 December 1920) | Theodore Hill | Progressive (1920)}}| | Progressive |
| Newcastle | William Kearsley | Labor}}| | Labor | Death | (30 August 1921) | David Murray | Labor}}| | Labor |
| Stuart ¶ | Percy Brookfield | Industrial Socialist Labor}}| | Industrial Socialist | Murdered while trying to disarm a deranged man at Riverton | (30 August 1921) | Jabez Wright | Labor}}| | Labor |
| Balmain | John Storey | Labor}}| | Labor | Death | (18 October 1921) | Tom Keegan | Labor}}| | Labor |
| Goulburn ‡ | William Millard | Nationalist}}| | Nationalist | Death | (22 November 1921) | John Perkins | Nationalist}}| | Nationalist |
¶ The Speaker had received correspondence nominating two Independents from the 1920 election. However, the terms of the Parliamentary Elections (Casual Vacancies ) Act stated that a nomination to fill the vacancy had to come from a recognised party leader. Labor leader and Premier John Storey nominated Jabez Wright.[1] ‡Millard had been appointed to replace Augustus James and, as there were no further unsuccessful Nationalist candidates, the Parliamentary Elections (Casual Vacancies ) Act was amended to allow his replacement by another Nationalist supporter. Twenty-fourth Legislative Assembly 1917–1920 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Macquarie | Thomas Thrower | Labor}}| | Labor | Death | 12 July 1917 | Patrick McGirr | Labor}}| | Labor |
| Murray | Robert Scobie | Nationalist}}| | Nationalist | Death | 22 September 1917 | Brian Doe | Nationalist}}| | Nationalist |
| Gloucester | Richard Price | Independent}}| | Independent Liberal | Expelled after a Royal Commission found he had made "wanton lies" in an attack on the Lands Minister William Ashford | 10 November 1917 | Richard Price | Independent}}| | Independent Liberal |
| Cobar | Charles Fern | Labor}}| | Labor | Death | (1 June 1918) | Mat Davidson | Labor}}| | Labor |
| Upper Hunter | Mac Abbott | Nationalist}}| | Nationalist | Resigned | 8 June 1918 | William Cameron | Nationalist}}| | Nationalist |
| Monaro | Gus Miller | Labor}}| | Labor | Death | 23 November 1918 | John Bailey | Labor}}| | Labor |
| Petersham | John Cohen | Nationalist}}| | Nationalist | Accepted an appointment as a District Court Judge | 22 March 1919 | Sydney Shillington | Nationalist}}| | Nationalist |
| Paddington | John Osborne | Labor}}| | Labor | Accepted as appointment to the Metropolitan Meat Board | 24 May 1919 | Lawrence O'Hara | Labor}}| | Labor |
| Paddington | Lawrence O'Hara | Labor}}| | Labor | Death | 26 July 1919 | John Birt | Labor}}| | Labor |
Twenty-third Legislative Assembly 1913–1917 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Canterbury | Henry Peters | Labor}}| | Labor | Bankrupt | 10 October 1914 | George Cann | Labor}}| | Labor |
| Castlereagh | John Treflé | Labor}}| | Labor | Death | 20 February 1915 | Guy Arkins | Labor}}| | Labor |
| Clarence | John McFarlane | Liberal Reform }}| | Liberal Reform | Death | 14 August 1915 | William Zuill | Farmers and Settlers }}| | Farmers and Settlers |
| Armidale | George Braund | Liberal Reform }}| | Liberal Reform | Died on active service | (18 September 1915) | Herbert Lane | Liberal Reform }}| | Liberal Reform |
| Wollondilly | Frank Badgery | Liberal Reform }}| | Liberal Reform | Death | (2 October 1915) | George Fuller | Liberal Reform }}| | Liberal Reform |
| Willoughby | Edward Larkin | Labor}}| | Labor | Died on active service on 25 April 1915 | 25 September 1915 | John Haynes | Independent}}| | Independent |
| Drummoyne | George Richards | Liberal Reform }}| | Liberal Reform | Death | 22 January 1916 | Alexander Graff | Liberal Reform }}| | Liberal Reform |
| Parramatta | Tom Moxham | Liberal Reform }}| | Liberal Reform | Death | 12 February 1916 | Albert Bruntnell | Liberal Reform }}| | Liberal Reform |
| Bingara | George McDonald | Labor}}| | Labor | Resigned from Labor after the 1916 NSW Labor Conference passed a motion of no confidence in the Holman government | 10 June 1916 | George McDonald | Independent}}| | Independent Labor |
| Sturt | John Cann | Labor}}| | Labor | Accepted the position of Commissioner of Railways | 3 February 1917 | Percy Brookfield | Labor}}| | Labor |
Twenty-second Legislative Assembly 1910–1913 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Mudgee | Bill Dunn | Labor}}| | Labor | ¶ | 16 August 1911 | Bill Dunn | Labor}}| | Labor |
| Liverpool Plains | Henry Hoyle | Labor}}| | Labor | ¶ | 16 August 1911 | John Perry | Liberal Reform }}| | Liberal Reform |
| Liverpool Plains | John Perry | Liberal Reform }}| | Liberal Reform | ¶ | 28 October 1911 | William Ashford | Labor}}| | Labor |
| Cobar | Donald Macdonell | Labor}}| | Labor | ¶ | (7 October 1911) | Donald Macdonell | Labor}}| | Labor |
| Cobar | Donald Macdonell | Labor}}| | Labor | ¶ | (16 December 1911) | Charles Fern | Labor}}| | Labor |
| Yass | Niels Nielson | Labor}}| | Labor | ¶ | 19 July 1913 | Greg McGirr | Labor}}| | Labor |
| Maitland | John Gillies | Independent }}| | Independent Liberal | Death | 28 October 1911 | Charles Edward Nicholson | Liberal Reform }}| | Liberal Reform |
| Alexandria | John Dacey | Labor}}| | Labor | Death | 18 May 1912 | Simon Hickey | Labor}}| | Labor |
| Blayney | George Beeby | Labor}}| | Labor | Resigned from the ministry, parliament and party in protest at the power of the extra-parliamentary Labor Party executive | 23 January 1913 | George Beeby | Independent }}| | Independent |
| Wollondilly | William McCourt | Liberal Reform }}| | Liberal Reform | Death | 19 July 1913 | Frank Badgery | Liberal Reform }}| | Liberal Reform |
¶ Mudgee Labor MLA Bill Dunn and Liverpool Plains Labor MLA Henry Hoyle resigned from the Labor Party and Parliament on 25 July 1911 in protest at legislation on land ownership introduced by Lands Minister, Niels Nielson. As a result, Labor was left without a majority in the house and rather than face a vote of no confidence, the Ministry and Speaker resigned. This forced the House to be prorogued with the result that Cobar Labor MLA, Donald Macdonell, who was unwell but expected to recover, was automatically expelled for non-attendance during an entire session. By the time of the subsequent by-elections, Labor policy had been reversed and Nielsen had left the ministry. Dunn rejoined the party and successfully re-contested, the Mudgee by-election on 16 August 1911. Hoyle did not re-contest the Liverpool Plains by-election which was won by Liberal candidate, John Perry by three votes on the same day. This result was overturned on appeal and at the second by-election on 28 October, Labor candidate, William Ashford was successful. In Cobar, Macdonell was unopposed when re-elected on 7 October, but died three weeks later. The Labor candidate, Charles Fern was unopposed at the second by-election on 16 December. Denied further ministerial appointment Nielsen resigned from the seat of Yass and Labor candidate Greg McGirr won the resultant by-election on 19 July 1913. Twenty-first Legislative Assembly 1907–1910 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| St George | Joseph Carruthers | Liberal Reform }}| | Liberal Reform | Resigned | 20 May 1908 | William Taylor | Liberal Reform }}| | Liberal Reform |
| Sturt | Arthur Hill Griffith | Labor}}| | Labor | Resigned from parliament after a dispute with the Speaker | (21 November 1908) | Arthur Hill Griffith | Labor}}| | Labor |
| Northumberland | Matthew Charlton | Labor}}| | Labor | Resigned to successfully contest the federal seat of Hunter at the 1910 election | (23 March 1910) | William Kearsley | Labor}}| | Labor |
| Darling Harbour | John Norton | Independent}}| | Independent | Resigned to unsuccessfully contest a Senate seat at the 1910 election | 23 March 1910 | John Cochran | Labor}}| | Labor |
| Queanbeyan | Granville Ryrie | Liberal Reform }}| | Liberal Reform | Resigned to unsuccessfully contest the federal seat of Werriwa at the 1910 election | 23 March 1910 | John Cusack | Labor}}| | Labor |
| Upper Hunter | William Fleming | Liberal Reform }}| | Liberal Reform | Resigned to unsuccessfully contest the federal seat of New England at the 1910 election | 23 March 1910 | William Ashford | Labor}}| | Labor |
| Belmore | Edward O'Sullivan | Labor}}| | Labor | Death | 21 May 1910 | Patrick Minahan | Labor}}| | Labor |
Twentieth Legislative Assembly 1904–1907 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Rous | John Coleman | Liberal Reform }}| | Liberal Reform | Death | 11 February1905 | George Hindmarsh | Liberal Reform}}| | Liberal Reform |
| Ashfield | Frederick Winchcombe | Liberal Reform}}| | Liberal Reform | Extended Absence visiting England | 16 August 1905 | William Robson | Liberal Reform}}| | Liberal Reform |
| Queanbeyan | Alan Millard | Liberal Reform}}| | Liberal Reform | Criminal conviction: Fraud | 7 April 1906 | Granville Ryrie | Liberal Reform}}| | Liberal Reform |
| Surry Hills | John Norton | Independent}}| | Independent | Challenged William Holman to face a by-election | 21 July 1906 | Albert Bruntnell | Liberal Reform}}| | Liberal Reform |
| Cootamundra | William Holman | Labor}}| | Labor | Challenged to a by-election by John Norton | 17 July 1906 | William Holman | Labor}}| | Labor |
| Castlereagh | Hugh Macdonald | Labor}}| | Labor | Death | 24 November 1906 | John Treflé | Labor}}| | Labor |
| Blayney | Paddy Crick | Progressive}}| | Progressive | Expelled after being accused of bribery | 12 January 1907 | John Withington | Liberal Reform}}| | Liberal Reform |
Nineteenth Legislative Assembly 1901–1904 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Condobolin | Patrick Clara | Labor}}| | Labor | Election overturned on appeal | 4 November 1901 | Patrick Clara | Labor}}| | Labor |
| Sydney-Pyrmont | Samuel Smith | Labor}}| | Labor | Appointment to Arbitration Court | 24 May 1902 | John McNeill | Labor}}| | Labor |
| Inverell | William McIntyre | Progressive}}| | Progressive | Death | 31 May 1902 | George Jones | Labor}}| | Labor |
| Balmain South | Sydney Law | Labor}}| | Labor | Refused Caucus solidarity pledge | 6 December 1902 | Sydney Law | Independent}}| | Independent Labor |
| Tamworth | Raymond Walsh | Progressive}}| | Progressive | Bankruptcy | 4 April 1903 | John Garland | Liberal Reform}}| | Liberal Reform |
| Willoughby | George Howarth | Liberal Reform}}| | Liberal Reform | Bankruptcy | 9 September 1903 | Charles Wade | Liberal Reform}}| | Liberal Reform |
| Glen Innes | Francis Wright | Progressive}}| | Progressive | Death | 28 October 1903 | Follett Thomas | Liberal Reform}}| | Liberal Reform |
| Waratah | Arthur Hill Griffith | Labor}}| | Labor | Unsuccessful candidate for Senate at federal election | 5 December 1903 | Matthew Charlton | Labor}}| | Labor |
| Armidale | Edmund Lonsdale | Liberal Reform}}| | Liberal Reform | Successful candidate for New England at federal election | 12 December 1903 | Sydney Kearney | Liberal Reform}}| | Liberal Reform |
| Moree | William Webster | Labor}}| | Labor | Successful candidate for Gwydir at federal election | 12 December 1903 | Percy Stirton | Liberal Reform}}| | Liberal Reform |
| Illawarra | Archibald Campbell | Liberal Reform}}| | Liberal Reform | Death | 9 January 1904 | Edward Allen | Liberal Reform}}| | Liberal Reform |
| Ryde | Frank Farnell | Independent}}| | Independent Liberal | Appointment to Fisheries Board | 23 January 1904 | Edward Terry | Independent}}| | Independent Liberal |
Eighteenth Legislative Assembly 1898–1901 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Hastings and Macleay | Francis Clarke | Protectionist}}| | National Federal | Resigned to give Barton a seat | 23 September 1898 | Edmund Barton | Protectionist}}| | National Federal |
| Parramatta | William Ferris | Independent}}| | Independent Federalist | Election declared void on appeal | 26 October 1898 | William Ferris | Independent}}| | Independent Federalist |
| Northumberland | Richard Stevenson | Protectionist}}| | National Federal | Death | 20 July 1899 | John Norton | Independent}}| | Independent |
| Boorowa | James Mackay | Protectionist}}| | Protectionist | Appointed to Legislative Council | 23 September 1899 | Niels Nielsen | Labor}}| | Labor |
| Hastings and Macleay | Edmund Barton | Protectionist}}| | Protectionist | Resigned to take Constitution to London | 1 March 1900 | Francis Clarke | Protectionist}}| | Protectionist |
| Sydney-Phillip | Henry Copeland | Protectionist}}| | Protectionist | accepted post as Agent-General in London | 7 April 1900 | Daniel O'Connor | Protectionist}}| | Protectionist |
| Canterbury | Varney Parkes | Free Trade}}| | Free Trade | Resignation | 9 June 1900 | Sydney Smith | Free Trade}}| | Free Trade |
| Uralla-Walcha | William Henry Piddington | Protectionist}}| | Protectionist | Resignation | 9 June 1900 | William Henry Piddington | Protectionist}}| | Protectionist |
| Bathurst | Francis Bathurst Suttor | Protectionist}}| | Protectionist | Appointed to Legislative Council | 25 June 1900 | William Young | Protectionist}}| | Protectionist |
| Canterbury | Sydney Smith | Free Trade}}| | Free Trade | By-election result voided on appeal | 28 July 1900 | Thomas Taylor | Independent}}| | Independent |
| Bourke | William Davis | Protectionist}}| | Protectionist | Resignation | 15 September 1900 | William Davis | Protectionist}}| | Protectionist |
| Uralla-Walcha | William Henry Piddington | Protectionist}}| | Protectionist | Death | 27 October 1900 | Michael MacMahon | Protectionist}}| | Protectionist |
| Ashfield | Bernhard Wise | Protectionist}}| | Protectionist | Appointed to Legislative Council | 10 November 1900 | Frederick Winchcombe | Free Trade}}| | Free Trade |
| Hume | William Lyne | Protectionist}}| | Protectionist | Successfully contested Hume at 1901 Federal election | 17 April 1901 | Gordon McLaurin | Protectionist}}| | Protectionist |
Seventeenth Legislative Assembly 1895–1898 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Rylstone | John Fitzpatrick | Free Trade}}| | Free Trade | Election result voided on appeal | 14 October 1895 | John Fitzpatrick | Free Trade}}| | Free Trade |
| Sydney-Phillip | Richard Meagher | Protectionist}}| | Protectionist | Disgraced during Dean Affair | 17 October 1895 | Henry Copeland | Protectionist}}| | Protectionist |
| Waverley | Angus Cameron | Free Trade}}| | Free Trade | Death | 18 February 1896 | Thomas Jessep | Free Trade}}| | Free Trade |
| Cowra | Denis Donnelly | Protectionist}}| | Protectionist | Death | 27 March 1896 | Michael Phillips | Protectionist}}| | Protectionist |
| Lachlan | James Carroll | Protectionist}}| | Protectionist | Financial difficulties | (11 September 1896) | James Carroll | Protectionist}}| | Protectionist |
| Narrabri | Charles Collins | Free Trade}}| | Free Trade | Death | 3 June 1898 | Hugh Ross | Labor}}| | Labor |
| Sydney-Fitzroy | John McElhone | Independent}}| | Independent Free Trade | Death | 3 June 1898 | John Norton | Protectionist}}| | Protectionist |
Sixteenth Legislative Assembly 1894–1895 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Grenfell | George Greene | Free Trade}}| | Free Trade | Election result overturned on appeal (no by-election) | (25 October 1894) | Michael Loughnane | Labor}}| | Labor |
| Willoughby | Joseph Cullen | Free Trade}}| | Free Trade | Financial difficulty | 30 November 1894 | Edward Clark | Free Trade}}| | Free Trade |
| Tweed | John Willard | Labor}}| | Labor | Not a resident of NSW | 29 November 1894 | Joseph Kelly | Protectionist}}| | Protectionist |
| Boorowa | Thomas Slattery | Protectionist}}| | Protectionist | Resigned | 15 January 1895 | James Mackay | Protectionist}}| | Protectionist |
| Bowral | William McCourt | Protectionist}}| | Protectionist | Resigned | (19 February 1895) | William McCourt | Protectionist}}| | Protectionist |
| Canterbury | Varney Parkes | Free Trade}}| | Free Trade | Resigned | (14 June 1895) | Varney Parkes | Free Trade}}| | Free Trade |
Fifteenth Legislative Assembly 1891–1894 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Central Cumberland | Robert Ritchie | Free Trade}}| | Free Trade | Death | 29 August 1891 | Jacob Garrard | Free Trade}}| | Free Trade |
| Canterbury | John Wheeler | Free Trade}}| | Free Trade | Election result overturned on appeal (no by-election) | (2 September 1891) | James Eve | Free Trade}}| | Free Trade |
| Illawarra | John Nicholson | Labor}}| | Labor | Previous result voided on appeal | 3 October 1891 | John Nicholson | Labor}}| | Labor |
| Illawarra | Andrew Lysaght | Protectionist}}| | Protectionist | Previous result voided on appeal | 3 October 1891 | Archibald Campbell | Protectionist}}| | Protectionist |
| Bourke | James Howe | Protectionist}}| | Protectionist | Resigned | 4 December 1891 | Thomas Waddell | Protectionist}}| | Protectionist |
| Bogan | George Cass | Protectionist}}| | Protectionist | Death | 31 May 1892 | William A'Beckett | Free Trade}}| | Free Trade |
| Hawkesbury | Alexander Bowman | Free Trade}}| | Free Trade | Death | 23 July 1892 | Sydney Burdekin | Free Trade}}| | Free Trade |
| East Macquarie | James Tonkin | Free Trade}}| | Free Trade | Financial Difficulty | 13 August 1892 | James Tonkin | Free Trade}}| | Free Trade |
| South Sydney | James Toohey | Protectionist}}| | Protectionist | Resigned | 13 February 1893 | William Manning | Protectionist}}| | Protectionist |
| Murrumbidgee | George Dibbs | Protectionist}}| | Protectionist | Financial Difficulty | (6 April 1893) | George Dibbs | Protectionist}}| | Protectionist |
| Central Cumberland | John Nobbs | Free Trade}}| | Free Trade | Financial Difficulty | 6 May 1893 | George McCredie | Free Trade}}| | Free Trade |
| Macleay | Otho Dangar | Protectionist}}| | Protectionist | Financial Difficulty | 29 May 1893 | Francis Clarke | Protectionist}}| | Protectionist |
Fourteenth Legislative Assembly 1889–1891 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Tamworth | Robert Levien | Protectionist}}| | Protectionist | Sought a new mandate after being involved in a legal scandal | (18 June 1889) | Robert Levien | Protectionist}}| | Protectionist |
| Central Cumberland | John Linsley | Free Trade}}| | Free Trade | Death | 22 July 1889 | David Dale | Free Trade}}| | Free Trade |
| Redfern | John Sutherland | Protectionist}}| | Protectionist | Death | 8 July 1889 | William Schey | Protectionist}}| | Protectionist |
| Central Cumberland | Frank Farnell | Free Trade}}| | Free Trade | Financial difficulty | (5 October 1889) | Frank Farnell | Free Trade}}| | Free Trade |
| Newcastle | William Grahame | Protectionist}}| | Protectionist | Financial Difficulty | 12 October 1889 | James Curley | Free Trade}}| | Free Trade |
| Monaro | Harold Stephen | Protectionist}}| | Protectionist | Death | 17 December 1889 | Gus Miller | Protectionist}}| | Protectionist |
| Hastings and Manning | Charles Roberts | Free Trade}}| | Free Trade | Resigned | 5 April 1890 | Walter Vivian | Free Trade}}| | Free Trade |
| Balmain | John Hawthorn | Free Trade}}| | Free Trade | Financial Difficulty | (12 July 1890) | John Hawthorn | Free Trade}}| | Free Trade |
| Hartley | John Hurley (b.1844) | Free Trade}}| | Free Trade | Financial Difficulty | 22 July 1890 | John Hurley (b.1844) | Free Trade}}| | Free Trade |
| Namoi | Thomas Dangar Jr. | Free Trade}}| | Free Trade | Death | 31 July 1890 | Charles Collins | Protectionist}}| | Protectionist |
| Goulburn | | Free Trade}}| | Free Trade | Death | 16 August 1890 | Cecil Teece | Independent}}| | Independent |
| West Sydney | Alfred Lamb | Free Trade}}| | Free Trade | Death | 25 October 1890 | Adolphus Taylor | Independent}}| | Independent |
| West Macquarie | Paddy Crick | Protectionist}}| | Protectionist | Expelled for outrageous behaviour in the chamber | 6 December 1890 | Paddy Crick | Protectionist}}| | Protectionist |
| Newcastle | James Fletcher | Protectionist}}| | Protectionist | Death | 14 April 1891 | William Grahame | Protectionist}}| | Protectionist |
| East Sydney | John Street | Free Trade}}| | Free Trade | Death | 14 April 1891 | Walter Bradley | Protectionist}}| | Protectionist |
| Wellington | David Ferguson | Protectionist}}| | Protectionist | Death | 29 May 1891 | Thomas York | Protectionist}}| | Protectionist |
Thirteenth Legislative Assembly 1887–1889 |
| By-election | Incumbent | Party | Reason for By-election | Date of By-election | Winner of By-election | Party |
|---|
| Mudgee | Adolphus Taylor | Free Trade}}| | Free Trade | Accepted position as Examiner of Patents | 11 May 1887 | John Haynes | Free Trade}}| | Free Trade |
| Wentworth | William MacGregor | Independent}}| | Independent Free Trade | Resigned | 28 September 1887 | Thomas Browne | Protectionist}}| | Protectionist |
| St Leonards | Henry Parkes | Free Trade}}| | Free Trade | Financial Difficulty | (25 October 1887) | Henry Parkes | Free Trade}}| | Free Trade |
| Central Cumberland | Andrew McCulloch | Free Trade}}| | Free Trade | Financial difficulty | 28 December 1887 | Andrew McCulloch | Free Trade}}| | Free Trade |
| Paddington | William Trickett | Free Trade}}| | Free Trade | Appointed to Legislative Council | 12 January 1888 | William Allen | Protectionist}}| | Protectionist |
| Newtown | Frederick Gibbes | Protectionist}}| | Protectionist | Death | 3 February 1888 | Joseph Abbott | Free Trade}}| | Free Trade |
| Newtown | William Foster | Free Trade}}| | Free Trade | Appointed Supreme Court Judge | 25 February 1888 | Joseph Mitchell | Free Trade}}| | Free Trade |
| Central Cumberland | Varney Parkes | Free Trade}}| | Free Trade | Business Commitments | 14 March 1888 | John Nobbs | Free Trade}}| | Free Trade |
| Central Cumberland | Andrew McCulloch | Free Trade}}| | Free Trade | Financial Difficulty | 15 May 1888 | David Buchanan | Protectionist}}| | Protectionist |
| Redfern | James Farnell | Free Trade}}| | Free Trade | Death | 8 September 1888 | James Howe | Protectionist}}| | Protectionist |
| Gunnedah | Thomas Goodwin | Protectionist}}| | Protectionist | Resigned | 12 September 1888 | Edwin Turner | Free Trade}}| | Free Trade |
|
Twelfth Legislative Assembly 1885–1887 |
|
| By-election | Incumbent | Reason for By-election | Date of By-election | Winner of By-election |
|---|
| Young | William Watson | Election result overturned by the Qualifications Committee (no by-election) | (22 December 1885) | James MacKinnon |
| Gwydir | William Campbell | Resigned | 10 June 1886 | Thomas Hassall |
| Mudgee | John Robertson | Retired (ill-health, financial difficulties and loss of premiership) | (2 July 1886) | William Wall |
| Wollombi | Lyall Scott | Retired (ill-health) | 17 December 1886 | Richard Stevenson |
| Yass Plains | Louis Heydon | Retired | 20 December 1886 | Thomas Colls |
| New England | William Proctor | Resigned | 10 January 1887 | William Proctor |
| Kiama | Harman Tarrant | Resigned | 13 January 1887 | Angus Cameron |
Eleventh Legislative Assembly 1882–1885 |
|
| By-election | Incumbent | Reason for By-election | Date of By-election | Winner of By-election |
|---|
| Newtown | Henry Copeland | Ministerial (defeated) | 13 January 1883 | Joseph Mitchell |
| East Sydney | John McElhone | Elected to two seats | 23 January 1883 | Henry Copeland |
| Mudgee | Adolphus Taylor | Challenged John McElhone to resign | 6 March 1883 | Adolphus Taylor |
| Upper Hunter | John McElhone | Challenged by Adolphus Taylor to resign | 6 March 1883 | John McElhone |
| Glebe | George Allen | Prolonged voyage to England. | 26 August 1883 | Michael Chapman |
| Bathurst | Francis Bathurst Suttor | Found to have a position of profit under the crown | (11 February 1884) | Francis Bathurst Suttor |
| East Sydney | George Reid | Found to have a position of profit under the crown | 29 February 1884 | Sydney Burdekin |
| Canterbury | William Pigott | Resigned (private work commitments) | 19 April 1884 | Mark Hammond |
| Gundagai | Bruce Smith | Resigned | 22 April 1884 | James Watson |
| Northumberland | Atkinson Tighe | Resigned | 26 May 1884 | Richard Luscombe |
| West Macquarie | Thomas Hellyer | Resigned | 2 July 1884 | Lewis Lloyd |
| Monaro | Robert Tooth | Resigned | (24 July 1884) | David Ryrie |
| Tenterfield | Henry Parkes | Resigned, claiming that he was retiring from politics | (24 November 1884) | Charles Lee |
| Carcoar | Andrew Lynch | Death | 21 November 1884 | Ezekial Baker |
| Argyle | John Gannon | Ill health | 31 March 1885 | Henry Parkes |
| St Leonards | Bernhardt Holtermann | Death | 4 June 1885 | Isaac Ives |
| Canterbury | Henry Moses | Accepted nomination to the Legislative Council | 16 September 1885 | William Henson |
| Central Cumberland | John Lackey | Accepted nomination to the Legislative Council | 24 September 1885 | Varney Parkes. |
Tenth Legislative Assembly 1880–1882 |
|
| By-election | Incumbent | Reason for By-election | Date of By-election | Winner of By-election |
|---|
| Queanbeyan | James Thompson | Resigned | 21 January 1881 | Thomas Rutledge |
| Carcoar | Ezekial Baker | Expelled after he had been found to have fraudulently dealt with trust funds | 1 December 1881 | George Campbell |
| Newtown | Stephen Brown | Appointed to the Legislative Council | 1 December 1881 | Joseph Mitchell |
| Argyle | Phillip Myers | Death | 9 December 1881 | John Gannon |
| Yass Plains | Michael Fitzpatrick | Death | 10 January 1882 | Louis Heydon |
| Redfern | John Sutherland | Appointed to the Legislative Council | 11 January 1882 | Francis Wright |
| Mudgee | Samuel Terry | Appointed to the Legislative Council | (20 January 1882) | John Robertson |
| Northumberland | William Turner | Resigned (He was supported by the local coal miners union, however the subscriptions were insufficient to support him in the assembly) | 18 January 1882 | Thomas Hungerford |
| East Macquarie | Edmund Webb | Appointed to the Legislative Council | 19 January 1882 | Alfred Pechey |
| Wentworth | William Brodribb | Appointed to the Legislative Council | 23 January 1882 | Edward Quin |
| Tenterfield | John Dillon | Resigned | 6 February 1882 | Augustus Fraser |
| East Macquarie | Alfred Pechey | Death | 11 July 1882 | Sydney Smith |
| Tumut | James Hoskins | Resigned to take a recuperative sea voyage | 17 October 1882 | Thomas O'Mara |
| Gundagai | William Forster | Death | 23 November 1882 | Bruce Smith |
Ninth Legislative Assembly 1877–1880 |
|
| By-election | Incumbent | Reason for By-election | Date of By-election | Winner of By-election |
|---|
| East Macquarie | John Robertson | Elected to two seats, | 1 February 1878 | Edmund Webb |
| East Maitland | Stephen Scholey | Death | 5 June 1878 | Henry Badgery |
| Mudgee | John Robertson | Appointed to the Legislative Council | 6 January 1879 | Richard Rouse |
| Orange | Edward Combes | Found to have an office of profit under the crown | 4 March 1879 | Andrew Kerr |
| Mudgee | Richard Rouse | Result overturned by the Qualifications Committee (no by-election) | (7 March 1879) | David Buchanan |
| East Macquarie | William Suttor, Jr. | Resigned | 15 August 1879 | Edward Combes |
| University of Sydney | William Windeyer | Accepted a position as a Judge of the Supreme Court | 26 August 1879 | Edmund Barton |
| East Sydney | Alexander Stuart | Accepted position as Agent-General in London | 17 December 1879 | Arthur Renwick |
| Paddington | John Sutherland | Found to have a position of profit under the crown | 20 February 1880 | William Hezlet |
| Clarence | Thomas Bawden | Found to have a position of profit under the crown | 7 April 1880 | Charles Fawcett |
| Northumberland | Thomas Hungerford | Resigned ( attend to personal business matters) | 30 April 1880 | Ninian Melville |
| Kiama | Samuel Charles | Prolonged voyage to Europe | 2 July 1880 | Harman Tarrant |
| Illawarra | Samuel Gray | Resigned | 7 July 1880 | Alexander Stuart |
| Windsor | Richard Driver | Death | 29 July 1880 | Henry McQuade |
Eighth Legislative Assembly 1874–1877 |
|
| By-election | Incumbent | Reason for By-election | Date of By-election | Winner of By-election |
|---|
| Paterson | William Arnold | Death | 18 March 1875 | Herbert Brown |
| Upper Hunter | Francis White | Death | 7 June 1875 | Thomas Hungerford |
| Central Cumberland | Joseph Wearne | Financial difficulties | 28 June1875 | William Long |
| Upper Hunter | Thomas Hungerford | Result voided by Qualifications Committee | 31 March 1873 | Thomas Robertson |
| Murrumbidgee | William Forster | Accepted the position of assistant to the Agent-General Charles Cowper | (6 March 1876) | Joseph Leary |
| Parramatta | Hugh Taylor | Resigned as he believed he had a position of profit under the crown | 20 April 1876 | Hugh Taylor |
| Hartley | Thomas Browne | Found to have held a position of profit under the crown | 21 April 1876 | John Hurley (b.1844) |
| Liverpool Plains | Hanley Bennett | Financial difficulties | 5 June 1876 | Hanley Bennett |
| Carcoar | Solomon Meyer | Resigned in May 1876 | (21 June 1876) | Andrew Lynch |
| University of Sydney | New Seat | 8 September 1876 | William Windeyer |
| Mudgee | Stephen Goold | Death | 5 October 1876 | Richard Rouse |
| Williams | William Watson | Resigned | February 1877 | William Johnston |
| Orange | Harris Nelson | Resigned | (22 February 1877) | Edward Combes |
| Northumberland | Charles Stevens | Financial difficulties | 20 July 1877 | William Turner |
Seventh Legislative Assembly 1872–1874 |
|
| By-election | Incumbent | Reason for By-election | Date of By-election | Winner of By-election |
|---|
| Parramatta | Hugh Taylor | Disqualified himself at the declaration of the poll as he had a position of profit under the crown | (22 May 1872) | Hugh Taylor |
| East Sydney | Saul Samuel | Appointed to the Legislative Council | 12 June 1872 | George Oakes |
| Murray | Patrick Jennings | Resigned | 5 August 1872 | William Hay |
| Hume | James McLaurin | Resigned | 31 March 1873 | Thomas Robertson |
| Mudgee | Joseph Innes | Appointed to the Legislative Council | 8 September 1873 | Joseph O'Connor |
| East Macquarie | James Martin | Accepted appointment as Chief Justice | 1 December 1873 | Walter Cooper |
| East Sydney | James Neale | Resigned | 15 July 1874 | Charles Moore |
| West Maitland | Benjamin Lee | Financial difficulties | 4 August 1874 | Lewis Levy |
Sixth Legislative Assembly 1869–1872 |
|
| By-election | Incumbent | Reason for By-election | Date of By-election | Winner of By-election |
|---|
| East Sydney | Henry Parkes | Elected to two seats | 23 February 1870 | John Wilson |
| West Sydney | John Robertson | Financial difficulties | 2 March 1870 | John Robertson |
| Goldfields North | Robert Wisdom | Elected to two seats | 18 April 1870 | Robert Forster |
| Goldfields South | Ezekiel Baker | Resigned | (11 July 1870) | Ezekiel Baker |
| Hastings | Horace Dean | Found to have held an office of profit under the crown | 4 July 1870 | Horace Dean |
| Wollombi | Joseph Eckford | Financial difficulties | 19 September 1870 | Joseph Eckford |
| Hastings | Horace Dean | Election overturned as not a British subject (no by-election) | (4 July 1870) | Robert Smith |
| Braidwood | Michael Kelly | Result voided due to electoral irregularities | 17 October 1870 | Edward Greville |
| Kiama | Henry Parkes | Financial difficulties | 3 November 1870 | Henry Parkes |
| Monaro | Daniel Egan | Death | 17 November 1870 | James Hart |
| Goldfields South | Ezekiel Baker | Accepted appointment to the Goldfields Royal Commission | 12 December 1870 | Ezekiel Baker |
| Canterbury | Montagu Stephen | Prolonged visit to England | 6 January 1871 | John Lucas |
| Kiama | Henry Parkes | Financial difficulties | (12 January 1871) | John Stewart |
| Liverpool Plains | Charles Cowper | Accepted the position of Agent-General in London | 9 January 1871 | Lewis Levy |
| Shoalhaven | Thomas Garrett | Accepted the position of Police Magistrate at Berrima | (28 August 1871) | James Warden |
| New England | Charles Weaver | Resigned | 28 August 1871 | Samuel Terry |
| Mudgee | Henry Stephen | Resigned | 2 January 1872 | Henry Parkes |
Fifth Legislative Assembly 1864–1869 |
|
| By-election | Incumbent | Reason for By-election | Date of By-election | Winner of By-election |
|---|
| Canterbury | John Lucas | Elected to two seats | 24 February 1865 | James Pemell |
| Monaro | James Martin | Elected to two seats | (10 April 1865) | William Grahame |
| Gwydir | Thomas Dangar Jr. | Position of profit under the crown | 29 June 1865 | Thomas Dangar Jr. |
| West Sydney 1 | John Darvall | Retired to England | 7 July 1865 | Geoffrey Eagar |
| West Sydney 2 | John Robertson | Financial Difficulty | (20 October 1865) | John Robertson |
| Yass Plains | Peter Faucett | Appointed as a judge in the New South Wales Supreme Court | (6 November 1865) | Robert Isaacs |
| West Sydney | John Robertson | Ministerial by-election | 17 January 1866 | William Charles Windeyer |
| Williams 1 | Marshall Burdekin | Ministerial by-election | 22 January 1866 | Frederick Manton |
| Williams 2 | Frederick Manton | Financial Difficulty | 19 April 1866 | John Nowlan |
| Tumut | Charles Cowper Jnr | Absent from parliament without leave | 20 August 1866 | Edward Brown |
| Clarence | John Laycock | Cause of resignation is unknown | 27 August 1866 | John Robertson |
| Illawarra | Patrick Osborne | Prolonged trip to England | 6 September 1866 | John Stewart |
| East Sydney | John Caldwell | Financial Difficulty | (24 September 1866) | Robert Stewart |
| Bathurst | James Kemp | Cause of resignation is unknown | (24 December 1866) | William Suttor |
| Goldfields West | Stephen Donnelly | Cause of resignation is unknown | 26 February 1867 | George Thornton |
| East Sydney | Charles Cowper | Financial Difficulty | 20 March 1867 | Marshall Burdekin |
| Central Cumberland | John Hay | Appointed to the Legislative Council | 27 June 1867 | John Lackey |
| Orange | William Forlonge | Financial Difficulty | 1 July 1867 | George McKay |
| East Macquarie | David Buchanan | Traveled to England to study for the bar | 26 August 1867 | John Suttor |
| Upper Hunter | James White | Prolonged trip to England | 6 June 1868 | Archibald Bell |
| Illawarra | George Pickering | Cause of resignation is unknown | 6 July 1868 | James Hoskins |
| Canterbury | James Pemell | Cause of resignation is unknown | (19 September 1868) | Richard Hill |
| West Sydney | Samuel Joseph | Prolonged trip to England | 15 December 1868 | William Campbell |
| Central Cumberland | Allan Macpherson | Cause of resignation is unknown | 17 December 1868 | Samuel Lyons |
| Goldfields West | George Thornton | Prolonged trip to England | 15 February 1869 | Walter Church |
| Braidwood | Joshua Josephson | Appointed a district court judge | (25 September 1869) | Michael Kelly |
Fourth Legislative Assembly 1860–1864 |
|
| By-election | Incumbent | Reason for By-election | Date of By-election | Winner of By-election |
|---|
| Parramatta | James Byrnes | Resigned (unhappy that he was the second member elected for the seat) | 10 April 1861 | Arthur Holroyd |
| Upper Hunter | John Robertson | Appointed to the Legislative Council | 15 April 1861 | Thomas Dangar |
| East Sydney | Henry Parkes | Accepted position as immigration promoter in England | 29 May 1861 | William Forster |
| Goulburn | Charles Walsh | Resigned as he had achieved his aim of Legislative Council reform | 13 June 1861 | Maurice Alexander |
| Patrick's Plains | William Lesley | Resigned | (8 July 1861) | Joseph Harpur |
| Newtown | Alexander McArthur | Appointed to the Legislative Council | 12 July 1861 | Thomas Holt |
| Lower Hunter | Alexander Scott | Appointed to the Legislative Council | 19 July 1861 | Richard Sadleir |
| Hunter | Isidore Blake | Resigned | 5 August 1861 | John Burns |
| Camden | John Douglas | Resigned on 17 July 1861 | (20 August 1861) | David Bell |
| Yass Plains | Henry O'Brien | Resigned (Ill health) | (22 August 1861) | Peter Faucett |
| Tenterfield | Robert Meston | Resigned | 3 December 1861 | Hugh Gordon |
| Shoalhaven | John Garrett | Resigned | (14 January 1862) | John Robertson |
| Wellington | Silvanus Daniel | Resigned | (5 March 1862) | Saul Samuel |
| New England | George Markham | Resigned | 2 April 1862 | Robert Forster |
| Orange | John Peisley | Resigned | 28 June 1862 | James Martin |
| Morpeth | David Buchanan | Financial difficulty | 18 September 1862 | Edward Close |
| Carcoar | William Watt | Resigned | (20 October 1862) | William Dalley |
| Argyle | Terence Murray | Appointed to the Legislative Council | (4 November 1862) | Samuel Emmanuel |
| Northumberland | Thomas Lewis | Financial difficulty | 23 December 1862 | Atkinson Tighe |
| West Sydney | William Windeyer | Resigned (Ill health after being shipwrecked) | 8 January 1863 | Geoffrey Eagar |
| Liverpool Plains | Alexander Dick | Resigned | 29 January 1863 | Marshall Burdekin |
| Goldfields North | James Hoskins | Accepted position as overseer of northern roads | 7 April 1863 | James Buchanan |
| Central Cumberland | James Atkinson | Resigned (Ill health) | 6 June 1863 | Allan Macpherson |
| East Maitland | James Dickson | Death | 18 June 1863 | John Darvall |
| Clarence | Clark Irving | Absent for entire session without leave | 23 July 1863 | Clark Irving |
| Orange | James Martin | Ministerial – Premier (defeated) | 4 November 1863 | Charles Cowper, Jr. |
| Tumut | Charles Cowper, Jr. | Resigned to oppose Martin in Ministerial by-election | 16 November 1863 | James Martin |
| Braidwood | Merion Moriarty | Death | 3 February 1864 | Henry Milford |
| Kiama | Samuel Gray | Resigned | 29 April 1864 | Henry Parkes |
| East Macquarie | William Suttor | Resigned | 6 October 1864 | David Buchanan |
Third Legislative Assembly 1859–1860 |
|
| By-election | Incumbent | Reason for By-election | Date of By-election | Winner of By-election |
|---|
| East Maitland | Joseph Chambers | Appointed Crown Prosecutor | 15 September 1859 | James Dickson |
| Yass Plains | Thomas Laidlaw | Found to have a position of profit under the crown | (20 September 1859) | Thomas Laidlaw |
| East Macquarie | William Suttor | Resigned | 6 October 1859 | Thomas Hawkins |
| Illawarra | John Hargrave | Appointed to Legislative Council | 28 October 1859 | Samuel Gordon |
| East Sydney | Charles Cowper | Resigned (Ill health) | 10 November 1859 | Charles Cowper |
| Mudgee | Lyttleton Bayley | Resigned after losing ministerial post | 19 December 1859 | Samuel Terry |
| West Macquarie | John McPhillamy | Resigned | (28 December 1859) | Henry Mort |
| East Sydney | Charles Cowper | Was nominated and elected without his consent at previous by-election | 20 January 1860 | Peter Faucett |
| Canterbury | Edward Flood | Resigned | 4 February 1860 | John Lucas |
| Williams | Stephen Dark | Resigned | 16 February 1860 | Alexander Campbell |
| Windsor | William Dalley | Prolonged visit to Europe resulting by-election | 12 March 1860 | William Walker |
| Liverpool Plains | Andrew Loder | Resigned after the defeat of the Foster Government | 10 April 1860 | Charles Kemp |
| Hunter | Richard Jones | Resigned | (25 April 1860) | Isidore Blake |
| St Leonards | Edward Sayers | Resigned | 2 May 1860 | James Farnell |
| East Macquarie | Thomas Hawkins | Resigned | 10 May 1860 | Daniel Deniehy |
| Tumut | George Lang | Resigned (political ennui) | 10 May 1860 | Daniel Deniehy |
| Wollombi | William Cape | Resigned | 17 May 1860 | Joseph Eckford |
| Wellington | Nicolas Hyeronimus | Death | 26 July 1860 | Silvanus Daniel |
| Morpeth | Edward Close | Resigned | 7 August 1860 | Samuel Cohen |
| Braidwood | Frederick Cooper | Resigned | 10 August 1860 | Merion Moriarty |
| Tumut | Daniel Deniehy | Elected to two seats and previous by-election voided due to voting irregularities | (8 November 1860) | Charles Cowper, Jr. |
Second Legislative Assembly 1858–1859 |
|
| By-election | Incumbent | Reason for By-election | Date of By-election | Winner of By-election |
|---|
| Cumberland (North Riding) | Henry Parkes | Financial difficulties | (20 September 1858) | John Plunkett |
| New England and Macleay | Abram Moriarty | Resigned | (14 December 1858) | James Hart |
| East Camden | Robert Owen | Accepted appointment to the District Court | 21 March 1859 | John Hargrave |
First Legislative Assembly 1856–1858 |
|
| By-election | Incumbent | Reason for By-election | Date of By-election | Winner of By-election |
|---|
| Western Division of Camden | James Macarthur | Believed poll to be unconstitutional | (21 June 1856) | James Macarthur |
| Bathurst County | John Plunkett | Elected for two seats | 19 June 1856 | William Suttor |
| Northumberland Boroughs | Bourn Russell | Result overturned by Qualifications Committee (no by-election) | (5 August 1856) | Elias Weekes |
| Cumberland (South Riding) | Elias Weekes | Elected for two seats | 21 August 1856 | John Brenan |
| Sydney Hamlets | Stuart Donaldson | Ministerial (defeated) | 10 October 1856 | John Campbell |
| Cumberland (South Riding) | John Brenan | Result voided on appeal | (7 November 1856) | Stuart Donaldson |
| Sydney City | Henry Parkes | Financial difficulties | 29 December 1856 | William Dalley |
| Argyle | John Plunkett | Appointed to the Legislative Council | (17 February 1857) | Daniel Deniehy |
| Cumberland (South Riding) | William Manning | Resigned | 12 June 1857 | James Byrnes |
| Northumberland Boroughs | George Nichols | Death | (6 November 1857) | James Dickson |
| Moreton, Wide Bay, Burnett and Maranoa | Gordon Sandeman | Resigned | (17 December 1857) | Patrick Leslie |
| Cumberland (North Riding) | John Darvall | Resigned | 11 December 1857 | Thomas Smith |
|
A by-election may occur whenever there is a vacancy in the Legislative Assembly.
It is now a convention that a by-election is not held if a vacancy occurs within 3–4 months of an expected dissolution of the parliament.
1. ^{{Cite web|url=http://www.parliament.nsw.gov.au/resources/nswelectionsanalysis/HomePage.htm |title=NSW Elections Analysis |accessdate=12 January 2009 |author=Antony Green |date= |work= |publisher=New South Wales Parliament |deadurl=yes |archiveurl=https://web.archive.org/web/20100625080533/http://www.parliament.nsw.gov.au/resources/nswelectionsanalysis/homepage.htm |archivedate=25 June 2010 |df= }}