List of Ontario by-elections

The list of Ontario by-elections includes every by-election held in the Canadian province of Ontario. By-elections occur whenever there is a vacancy in the Legislative Assembly, although an imminent general election may allow the vacancy to remain until the dissolution of parliament.

Causes

A by-election occurs whenever there is a vacancy in the Ontario legislature. Vacancies can occur for the following reasons:

• Death of a member.
• Resignation of a member.
• Voided results
• Expulsion from the legislature.
• Ineligibility to sit.

When there is a vacancy, a by-election must be called within six months. Under amendments to the Election Act approved in 2016, a by-election is no longer required when a vacancy occurs in the 12 months leading up to a fixed general election date.

Ministerial by-elections

The list includes ministerial by-elections which occurred due to the requirement that incumbent members recontest their seats upon being appointed to Cabinet. These by-elections were almost always uncontested. This requirement was amended in 1926 to exempt ministers appointed within three months after a general election. In 1941 it was abolished completely.

43rd Legislative Assembly of Ontario 2022–present

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Hamilton Centre	TBA	Andrea Horwath		New Democratic				Resigned to run for Mayor of Hamilton, elected.

42nd Legislative Assembly of Ontario 2018–2022

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Ottawa—Vanier	February 27, 2020	Nathalie Des Rosiers		Liberal	Lucille Collard		Liberal	Resigned to become Principal of Massey College	Yes
Orléans	February 27, 2020	Marie-France Lalonde		Liberal	Stephen Blais		Liberal	Resigned to run in the federal district of Orléans; elected.	Yes

41st Legislative Assembly of Ontario 2014–2018

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Sault Ste. Marie	June 1, 2017	David Orazietti		Liberal	Ross Romano		Progressive Conservative	Resignation.	No
Niagara West—Glanbrook	November 17, 2016	Tim Hudak		Progressive Conservative	Sam Oosterhoff		Progressive Conservative	Resignation to become CEO of Ontario Real Estate Association.	Yes
Ottawa—Vanier	November 17, 2016	Madeleine Meilleur		Liberal	Nathalie Des Rosiers		Liberal	Resignation.	Yes
Scarborough—Rouge River	September 1, 2016	Bas Balkissoon		Liberal	Raymond Cho		Progressive Conservative	Resignation.	No
Whitby—Oshawa	February 11, 2016	Christine Elliott		Progressive Conservative	Lorne Coe		Progressive Conservative	Resigned after losing leadership contest.	Yes
Simcoe North	September 3, 2015	Garfield Dunlop		Progressive Conservative	Patrick Brown		Progressive Conservative	Resignation to create a vacancy for PC leader Brown.	Yes
Sudbury	February 5, 2015	Joe Cimino		New Democratic	Glenn Thibeault		Liberal	Resignation.	No

40th Legislative Assembly of Ontario 2011–2014

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Thornhill	February 13, 2014	Peter Shurman		Progressive Conservative	Gila Martow		Progressive Conservative	Resignation	Yes
Niagara Falls	February 13, 2014	Kim Craitor		Liberal	Wayne Gates		New Democratic	Resignation	No
Scarborough—Guildwood	August 1, 2013	Margarett Best		Liberal	Mitzie Hunter		Liberal	Resignation	Yes
Etobicoke—Lakeshore	August 1, 2013	Laurel Broten		Liberal	Doug Holyday		Progressive Conservative	Resignation	No
Ottawa South	August 1, 2013	Dalton McGuinty		Liberal	John Fraser		Liberal	Resignation to re-enter private life after retiring as Premier and Liberal leader.	Yes
Windsor—Tecumseh	August 1, 2013	Dwight Duncan		Liberal	Percy Hatfield		New Democratic	Resignation following the retirement of Premier McGuinty	No
London West	August 1, 2013	Chris Bentley		Liberal	Peggy Sattler		New Democratic	Resignation following the retirement of Premier McGuinty	No
Kitchener—Waterloo	September 6, 2012	Elizabeth Witmer		Progressive Conservative	Catherine Fife		New Democratic	Resignation to accept appointment as Chair of the Workplace Safety & Insurance Board	No
Vaughan	September 6, 2012	Greg Sorbara		Liberal	Steven Del Duca		Liberal	Resignation	Yes

39th Legislative Assembly of Ontario 2007–2011

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Ottawa West—Nepean	March 4, 2010	Jim Watson		Liberal	Bob Chiarelli		Liberal	Resignation to run for Mayor of Ottawa	Yes
Leeds—Grenville	March 4, 2010	Robert Runciman		Progressive Conservative	Steve Clark		Progressive Conservative	Resignation upon appointment to Canadian Senate.	Yes
Toronto Centre	February 4, 2010	George Smitherman		Liberal	Glen Murray		Liberal	Resignation to run for Mayor of Toronto.	Yes
St. Paul's	September 17, 2009	Michael Bryant		Liberal	Eric Hoskins		Liberal	Resignation to accept municipal appointment.	Yes
Haliburton—Kawartha Lakes—Brock	March 5, 2009	Laurie Scott		Progressive Conservative	Rick Johnson		Liberal	Resignation to create vacancy for PC leader John Tory.	No

38th Legislative Assembly of Ontario 2003–2007

See also: 2007 Ontario provincial by-elections

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Burlington	February 8, 2007	Cam Jackson		Progressive Conservative	Joyce Savoline		Progressive Conservative	Resignation to run for Mayor of Burlington	Yes
York South—Weston	February 8, 2007	Joe Cordiano		Liberal	Paul Ferreira		New Democratic	Resignation	No
Markham	February 8, 2007	Tony Wong		Liberal	Michael Chan		Liberal	Resignation to run municipally.	Yes
Parkdale—High Park	September 14, 2006	Gerard Kennedy		Liberal	Cheri DiNovo		New Democratic	Resignation to seek federal Liberal leadership.	No
Whitby—Ajax	March 30, 2006	Jim Flaherty		Progressive Conservative	Christine Elliott		Progressive Conservative	Resignation to run federally.	Yes
Toronto—Danforth	March 26, 2006	Marilyn Churley		New Democratic	Peter Tabuns		New Democratic	Resignation to run federally.	Yes
Nepean—Carleton	March 26, 2006	John Baird		Progressive Conservative	Lisa MacLeod		Progressive Conservative	Resignation to run federally.	Yes
Scarborough—Rouge River	November 24, 2005	Alvin Curling		Liberal	Bas Balkissoon		Liberal	Resignation to accept diplomatic posting.	Yes
Dufferin—Peel—Wellington—Grey	March 17, 2005	Ernie Eves		Progressive Conservative	John Tory		Progressive Conservative	Resignation.	Yes
Hamilton East	May 13, 2004	Dominic Agostino		Liberal	Andrea Horwath		New Democratic	Death	No

37th Legislative Assembly of Ontario 1999–2003

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Dufferin—Peel—Wellington—Grey	May 2, 2002	David Tilson		Progressive Conservative	Ernie Eves		Progressive Conservative	Resignation to create vacancy for PC leader and Premier Ernie Eves.	Yes
Nipissing	May 2, 2002	Mike Harris		Progressive Conservative	Al McDonald		Progressive Conservative	Resignation after retiring as Premier and party leader.	Yes
Beaches-East York	September 20, 2001	Frances Lankin		New Democratic	Michael Prue		New Democratic	Resignation to become CEO of United Way Toronto	Yes
Vaughan—King—Aurora	June 28, 2001	Al Palladini		Progressive Conservative	Greg Sorbara		Liberal	Death	No
Parry Sound—Muskoka	March 22, 2001	Ernie Eves		Progressive Conservative	Norm Miller		Progressive Conservative	Resignation	Yes
Wentworth-Burlington	September 7, 2000	Toni Skarica		Progressive Conservative	Ted McMeekin		Liberal	Resignation to protest municipal amalgamation.	No

36th Legislative Assembly of Ontario 1995–1999

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Nickel Belt	October 1, 1998	Floyd Laughren		New Democratic	Blain Morin		New Democratic	Resignation to accept appointment as chair of Ontario Energy Board	Yes
Oriole	September 4, 1997	Elinor Caplan		Liberal	David Caplan		Liberal	Resignation to enter federal politics	Yes
Ottawa West	September 4, 1997	Bob Chiarelli		Liberal	Alex Cullen		Liberal	Resignation to run municipally	Yes
Windsor—Riverside	September 4, 1997	Dave Cooke		New Democratic	Wayne Lessard		New Democratic	Resignation to accept provincial appointment to the Education Improvement Commission.	Yes
York South	May 23, 1996	Bob Rae		New Democratic	Gerard Kennedy		Liberal	Resignation.	No

35th Legislative Assembly of Ontario 1990–1995

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Victoria—Haliburton	March 17, 1994	Dennis Drainville		Independent	Chris Hodgson		Progressive Conservative	Resignation to run federally.	No
Essex South	December 2, 1993	Remo Mancini		Liberal	Bruce Crozier		Liberal	Resignation	Yes
St. George—St. David	April 1, 1993	Ian Scott		Liberal	Tim Murphy		Liberal	Resignation	Yes
Don Mills	April 1, 1993	Margery Ward		New Democratic	David Johnson		Progressive Conservative	Death	No
Brant—Haldimand	March 5, 1992	Robert Nixon		Liberal	Ronald Eddy		Liberal	Resignation to accept federal appointment.	Yes

34th Legislative Assembly of Ontario 1987–1990

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Welland—Thorold	November 3, 1988	Mel Swart		New Democratic	Peter Kormos		New Democratic	Resignation.	Yes
London North	March 31, 1988	Ron Van Horne		Liberal	Dianne Cunningham		Progressive Conservative	Resignation.	No

33rd Legislative Assembly of Ontario 1985–1987

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Cochrane North	August 14, 1986	René Fontaine		Liberal	René Fontaine		Liberal	Resignation from cabinet and legislature to resubmit candidacy to voters after it was revealed he had forgotten to disclose his ownership of shares in a mining company contrary to conflict of interest guidelines.	Yes
York East	April 17, 1986	Robert Elgie		Progressive Conservative	Christine Hart		Liberal	Resignation to accept appointment as head of Workers Compensation Board.	No

32nd Legislative Assembly of Ontario 1981–1985

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Wentworth North	December 13, 1984	Eric Cunningham		Liberal	Ann Sloat		Progressive Conservative	Resignation to run federally.	No
Prescott and Russell	December 13, 1984	Don Boudria		Liberal	Jean Poirier		Liberal	Resignation to run federally.	Yes
Ottawa East	December 13, 1984	Albert J. Roy		Liberal	Bernard Grandmaître		Liberal	Resignation to run federally.	Yes
Ottawa Centre	December 13, 1984	Michael Cassidy		New Democratic	Evelyn Gigantes		New Democratic	Resignation to run federally.	Yes
Hamilton Centre	December 13, 1984	Sheila Copps		Liberal	Mike Davison		New Democratic	Resignation to run federally.	No
Stormont—Dundas—Glengarry	December 15, 1983	Osie Villeneuve		Progressive Conservative	Noble Villeneuve		Progressive Conservative	Death	Yes
York South	November 4, 1982	Donald C. MacDonald		New Democratic	Bob Rae		New Democratic	Resignation to create vacancy for NDP leader Bob Rae.	Yes
Hamilton West	June 17, 1982	Stuart Smith		Liberal	Richard Allen		New Democratic	Resignation from legislature after his successor as Liberal leader was chosen.	No

31st Legislative Assembly of Ontario 1977–1981

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Carleton	November 20, 1980	Sid Handleman		Progressive Conservative	Robert C. Mitchell		Progressive Conservative	Resignation	Yes
Scarborough West	April 5, 1979	Stephen Lewis		New Democratic	Richard Johnston		New Democratic	Resignation several months after his successor as Ontario NDP leader was chosen.	Yes
Wentworth	April 5, 1979	Ian Deans		New Democratic	Colin Isaacs		New Democratic	Resignation after being defeated in his candidacy to lead the Ontario NDP.	Yes
Sault Ste. Marie	December 14, 1978	John Rhodes		Progressive Conservative	Russ Ramsay		Progressive Conservative	Death.	Yes
Chatham—Kent	October 19, 1978	Darcy McKeough		Progressive Conservative	Andrew Naismith Watson		Progressive Conservative	Resignation.	Yes

30th Legislative Assembly of Ontario 1975–1977

no by-elections

29th Legislative Assembly of Ontario 1971–1975

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Carleton East	November 7, 1974	Bert Lawrence		Progressive Conservative	Paul Frederick Taylor		Liberal	Resignation.	No
Stormont	October 17, 1974	Fernand Guindon		Progressive Conservative	George Samis		New Democratic	Resignation to run federally.	No
Huron	March 15, 1973	Charles MacNaughton		Progressive Conservative	Jack Riddell		Liberal	Resignation.	No
St. George	March 15, 1973	Allan Lawrence		Progressive Conservative	Margaret Campbell		Liberal	Resignation to enter federal politics.	No

28th Legislative Assembly of Ontario 1967–1971

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Middlesex South	September 18, 1969	Neil Leverne Olde		Progressive Conservative	Kenneth Charles Bolton		New Democratic	Death.	No

27th Legislative Assembly of Ontario 1963–1967

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Kenora	September 22, 1966	Robert Wayne Gibson		Liberal-Labour	Leo Bernier		Progressive Conservative	Death	No
Nipissing	September 15, 1965	Leo Troy		Liberal	Richard Smith		Liberal	Death	Yes
Bracondale	September 15, 1965	Joseph M. Gould		Liberal	George Ben		Liberal	Death	Yes
Riverdale	September 10, 1964	Robert Macaulay		Progressive Conservative	Jim Renwick		New Democratic	Resigned to return to private live	No
Windsor—Sandwich	September 10, 1964	Maurice Belanger		Liberal	Ivan Thrasher		Progressive Conservative	Death	No

26th Legislative Assembly of Ontario 1959–1963

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Huron—Bruce	October 4, 1962	John William Hanna		Progressive Conservative	Murray Gaunt		Liberal	Death	No
Beaches	January 18, 1962	William Henry Collings		Progressive Conservative	Robert John Harris		Progressive Conservative	Death	Yes
Brant	January 18, 1962	Harry Nixon		Liberal	Robert Nixon		Liberal	Death	Yes
Eglinton	January 18, 1962	William James Dunlop		Progressive Conservative	Leonard Mackenzie Reilly		Progressive Conservative	Death	Yes
Kenora	January 18, 1962	Albert Wren		Liberal-Labour	Robert Wayne Gibson		Liberal	Death	Yes
Renfrew South	January 18, 1962	James Anthony Maloney		Progressive Conservative	Leonard Joseph Quilty		Liberal	Death	No
Simcoe Centre	September 29, 1960	George Graham Johnston		Progressive Conservative	David Arthur Evans		Progressive Conservative	Death	Yes
Timiskaming	September 29, 1960	Alexander Robert Herbert		Progressive Conservative	Phillip Hoffman		Progressive Conservative	Death	Yes

25th Legislative Assembly of Ontario 1955–1959

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Hastings East	August 28, 1958†	Roscoe Robson		Progressive Conservative	Lloyd Harrison Price		Progressive Conservative	Appointed Sheriff	Yes
Lanark	August 28, 1958†	John Arthur McCue		Progressive Conservative	George Gomme		Progressive Conservative	Death	Yes
Cochrane North	May 12, 1958	Philip Timothy Kelly		Progressive Conservative	René Brunelle		Progressive Conservative	Resignation	Yes
Huron	May 12, 1958	Thomas Pryde		Progressive Conservative	Charles MacNaughton		Progressive Conservative	Death	Yes
Renfrew North	May 12, 1958	Stanley Joseph Hunt		Progressive Conservative	Maurice Hamilton		Progressive Conservative	Resigned to enter federal politics	Yes
St. George	May 12, 1958	Dana Porter		Progressive Conservative	Allan Lawrence		Progressive Conservative	Appointed Chief Justice of the Ontario Court of Appeal	Yes
Elgin	January 30, 1958	Fletcher Stewart Thomas		Progressive Conservative	Ron McNeil		Progressive Conservative	Death	Yes
Lanark	October 24, 1957	George Doucett		Progressive Conservative	John Arthur McCue		Progressive Conservative	Resigned to enter federal politics	Yes
Glengarry	September 5, 1957	Osie Villeneuve		Progressive Conservative	Fernand Guindon		Progressive Conservative	Resigned to enter federal politics	Yes
Middlesex North	September 5, 1957	Thomas L. Patrick		Progressive Conservative	William Atcheson Stewart		Progressive Conservative	Death	Yes
York West	October 18, 1956	W. Elmer Brandon		Progressive Conservative	Leslie Rowntree		Progressive Conservative	Death	Yes
Renfrew South	January 12, 1956	James Shannon Dempsey		Progressive Conservative	James Anthony Maloney		Progressive Conservative	Death	Yes

† Won by acclamation

24th Legislative Assembly of Ontario 1951–1955

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Leeds	September 16, 1954	Charles Gordon MacOdrum		Progressive Conservative	James Auld		Progressive Conservative	Death	Yes
Nipissing	September 16, 1954	William Bruce Harvey		Progressive Conservative	Jean Marc Chaput		Progressive Conservative	Death	Yes
Russell	September 16, 1954	Joseph Daniel Nault		Progressive Conservative	Gordon Lavergne		Progressive Conservative	Death	Yes
Simcoe East	February 8, 1954	John Duncan McPhee		Progressive Conservative	Lloyd Averall Letherby		Progressive Conservative	Death	Yes
Niagara Falls	October 26, 1953	William Houck		Liberal	Arthur Connaught Jolley		Progressive Conservative	Resigned to enter federal politics	No

23rd Legislative Assembly of Ontario 1948–1951

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Leeds	October 31, 1949	Walter Bain Reynolds		Progressive Conservative	Hugh Alexander Reynolds		Progressive Conservative	Death	Yes
Cochrane North	June 8, 1949	John Carrère		Progressive Conservative	Marcel Léger		Progressive Conservative	Death	Yes
Parry Sound	December 9, 1948	Charles Wilson Cragg		Progressive Conservative	Allister Johnston		Progressive Conservative	Death	Yes

22nd Legislative Assembly of Ontario 1945–1948

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Huron	February 16, 1948	Robert Hobbs Taylor		Progressive Conservative	Thomas Pryde		Progressive Conservative	Death	Yes

21st Legislative Assembly of Ontario 1943–1945

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Haldimand—Norfolk	March 20, 1944	Wallace William Walsh		Progressive Conservative	Charles Hammond Martin		Progressive Conservative	Death	Yes

20th Legislative Assembly of Ontario 1937–1943

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Grey South	February 24, 1941†	Farquhar Oliver		United Farmers of Ontario	Farquhar Oliver		Liberal	Sought re-election upon appointment as Minister of Public Works	No
Ottawa East	November 27, 1940	Paul Leduc		Liberal	Robert Laurier		Liberal	Resignation	Yes
Simcoe Centre	October 23, 1940†	Leonard Jennett Simpson		Liberal	Duncan McArthur		Liberal	Death	Yes
Simcoe East	February 14, 1939†	William Finlayson		Conservative	George A. Drew		Conservative	Resignation to provide a seat for Conservative leader Drew	Yes
Parkdale	October 5, 1938	Fred McBrien		Conservative	William James Stewart		Conservative	Death	Yes
Waterloo South	September 28, 1938†	Norman Hipel		Liberal	Norman Hipel		Liberal	Sought re-election upon appointment as Minister of Labour	Yes
Brantford	July 20, 1938	Morrison Mann MacBride		Independent-Liberal*	Louis Hagey		Liberal	Death	Yes
Lambton East	March 22, 1938	Milton Duncan McVicar		Liberal	Charles Oliver Fairbank		Liberal	Death	Yes
Hamilton Centre	March 2, 1938	William Frederick Schwenger		Liberal	John Newlands		Liberal	Resigned to become a judge	Yes
Sault Ste. Marie	November 23, 1937†	Richard McMeekin		Liberal	Colin Campbell		Liberal	Resignation to provide a seat for Campbell	Yes

† Won by acclamation

*Though nominally an "Independent-Liberal", MacBride was a supporter of the Liberal government and was a cabinet minister at the time of his death

19th Legislative Assembly of Ontario 1934–1937

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Hastings East	December 9, 1936	James Ferguson Hill		Conservative	Harold Edward Welsh		Conservative	Death	Yes
Nipissing	March 4, 1935	Théodore Legault		Liberal	Joseph Marceau		Liberal	Death	Yes
Grey North	August 20, 1934	David James Taylor		Liberal-Progressive	Roland Patterson		Liberal-Progressive	Resigned to accept appointment as Deputy Minister of Game and Fisheries	Yes
Wellington South	August 20, 1934	Duncan Paul Munro		Liberal	James Harold King		Liberal	Death	Yes
Kenora	August 7, 1934†	Earl Hutchinson		Labour	Peter Heenan		Liberal	Resigned to become vice-chairman of Workmen's Compensation Board	No

† Won by acclamation

18th Legislative Assembly of Ontario 1929–1934

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Kent East	January 3, 1934†	Philip James Henry		Conservative	Douglas Munro Campbell		Liberal	Death	No
York West	May 28, 1932	Forbes Godfrey		Conservative	Henry Isaac Price		Conservative	Death	Yes
Wellington South	November 18, 1931	Lincoln Goldie		Conservative	Duncan Paul Munro		Liberal	Died	No
Dundas	August 29, 1931†	George Holmes Challies		Conservative	George Holmes Challies		Conservative	Sought re-election upon appointment as Provincial Secretary and Registrar	Yes
Norfolk	July 8, 1931	John Strickler Martin		Conservative	Arthur Campbell Burt		Conservative	Death	Yes
Grenville	February 11, 1931	Howard Ferguson		Conservative	James Alfred Sanderson		Conservative	Resigned to accept appointment as Canadian High Commissioner to the United Kingdom	Yes
Hamilton West	February 11, 1931	Frederick Thomas Smye		Conservative	D'Arcy Argue Counsell Martin		Conservative	Death	Yes
Lanark South	October 29, 1930	James Alexander Anderson		Conservative	Egerton Reuben Stedman		Conservative	Death	Yes
Nipissing	October 29, 1930	Henri Morel		Conservative	Charles Robert Harrison		Conservative	Resigned to run in the 1930 federal election	Yes
Perth South	October 29, 1930	David Bonis		Conservative	Charles Edward Richardson		Conservative	Death	Yes
Waterloo South	October 29, 1930	Karl Kenneth Homuth		Conservative	Norman Hipel		Liberal	Resigned to run in the 1930 federal election	No
Algoma	October 18, 1930†	John Morrow Robb		Conservative	John Morrow Robb		Conservative	Sought re-election upon appointment as Minister of Health	Yes
Brantford	October 18, 1930†	William George Martin		Conservative	William George Martin		Conservative	Sought re-election upon appointment as Minister of Public Welfare	Yes
Peel	October 18, 1930†	Thomas Laird Kennedy		Conservative	Thomas Laird Kennedy		Conservative	Sought re-election upon appointment as Minister of Agriculture	Yes
Renfrew North	October 18, 1930†	Edward Arunah Dunlop		Conservative	Edward Arunah Dunlop		Conservative	Sought re-election upon appointment as Provincial Treasurer	Yes
York South	October 18, 1930†	Leopold Macaulay		Conservative	Leopold Macaulay		Conservative	Sought re-election upon appointment as Provincial Secretary and Registrar	Yes

† Won by acclamation

17th Legislative Assembly of Ontario 1926–1929

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Renfrew North	June 27, 1928	Alexander Stuart		Conservative	Edward Arunah Dunlop		Conservative	Death	Yes
Bruce South	June 27, 1928	Malcolm Alex McCallum		Progressive	Foster Graham Moffatt		Conservative	Election declared void	No
Hamilton East	June 27, 1928	Leeming Carr		Conservative	William Robert Morrison		Conservative	Resigned to accept appointment as Sheriff of Wellington County	Yes
Prince Edward	November 1, 1927†	William Raney		United Farmers of Ontario	Horace Stanley Colliver		Conservative	Appointed to Supreme Court of Ontario	No

† Won by acclamation

16th Legislative Assembly of Ontario 1923–1926

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Toronto Northwest A	July 7, 1924	Thomas Crawford		Conservative	William Henry Edwards		Conservative	Resigned to accept appointment as Registrar	Yes
Waterloo South	June 23, 1924	Karl Kenneth Homuth		Labour	Karl Kenneth Homuth		Labour	Election declared void	Yes
Lennox	October 22, 1923	John Perry Vrooman		Liberal	Charles Wesley Hambly		Conservative	Death	No
York West	August 16, 1923†	Forbes Godfrey		Conservative	Forbes Godfrey		Conservative	Sought re-election upon appointment as Minister of Labour	Yes
York East	August 16, 1923†	George Stewart Henry		Conservative	George Stewart Henry		Conservative	Sought re-election upon appointment as Minister of Public Works and Highways	Yes
Wellington South	August 16, 1923†	Lincoln Goldie		Conservative	Lincoln Goldie		Conservative	Sought re-election upon appointment as Provincial Secretary and Registrar	Yes
Sudbury	August 16, 1923†	Charles McCrea		Conservative	Charles McCrea		Conservative	Sought re-election upon appointment as Minister of Mines	Yes
Sault Ste. Marie	August 16, 1923†	James Winfield Lyons		Conservative	James Winfield Lyons		Conservative	Sought re-election upon appointment as Minister of Lands and Forests	Yes
Parkdale	August 16, 1923†	William Herbert Price		Conservative	William Herbert Price		Conservative	Sought re-election upon appointment as Provincial Treasurer	Yes
Norfolk South	August 16, 1923†	John Strickler Martin		Conservative	John Strickler Martin		Conservative	Sought re-election upon appointment as Minister of Agriculture	Yes
Kingston	August 16, 1923†	William Folger Nickle		Conservative	William Folger Nickle		Conservative	Sought re-election upon appointment as Attorney-General	Yes
Grenville	August 16, 1923†	George Howard Ferguson		Conservative	George Howard Ferguson		Conservative	Sought re-election upon appointment as Premier and Minister of Education	Yes

† Won by acclamation

15th Legislative Assembly of Ontario 1919–1923

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Russell	October 23, 1922	Damase Racine		Liberal	Alfred Goulet		Liberal	Death	Yes
Toronto Southeast A	October 23, 1922	John O'Neill		Liberal	John Allister Currie		Conservative	Death	No
Kingston	February 6, 1922	Arthur Edward Ross		Conservative	William Folger Nickle		Conservative	Resigned to run in the 1921 federal election	Yes
Oxford North	December 19, 1921	John Alexander Calder		Liberal	David Munroe Ross		United Farmers of Ontario	Death	No
Toronto Northeast A	November 8, 1920	Henry John Cody		Conservative	Alexander Cameron Lewis		Conservative	Resignation	Yes
Fort William	July 19, 1920†	Harry Mills		Labour	Harry Mills		Labour	Sought re-election upon appointment as Minister of Mines	Yes
Wellington East	February 23, 1920†	Albert Hellyer		United Farmers of Ontario	William Raney		United Farmers of Ontario	Resignation to provide a seat for Raney	Yes
Halton	February 16, 1920	John Featherstone Ford		United Farmers of Ontario	Ernest Charles Drury		United Farmers of Ontario	Resignation to provide a seat for Drury	Yes
Kent East	February 9, 1920†	James B. Clark		United Farmers of Ontario	Manning Doherty		United Farmers of Ontario	Resignation to provide a seat for Doherty	Yes
Brant North	December 15, 1919†	Harry Nixon		United Farmers of Ontario	Harry Nixon		United Farmers of Ontario	Sought re-election upon appointment as Provincial Secretary and Registrar	Yes
Wentworth North	December 15, 1919†	Frank Campbell Biggs		United Farmers of Ontario	Frank Campbell Biggs		United Farmers of Ontario	Sought re-election upon appointment as Minister of Public Works and Highways	Yes
Perth South	December 15, 1919†	Peter Smith		United Farmers of Ontario	Peter Smith		United Farmers of Ontario	Sought re-election upon appointment as Provincial Treasurer	Yes
Manitoulin	December 15, 1919†	Beniah Bowman		United Farmers of Ontario	Beniah Bowman		United Farmers of Ontario	Sought re-election upon appointment as Minister of Lands, Forests and Mines	Yes
Hamilton West	December 15, 1919†	Walter Rollo		Labour	Walter Rollo		Labour	Sought re-election upon appointment as Minister of Labour	Yes
Carleton	December 15, 1919†	Robert Henry Grant		United Farmers of Ontario	Robert Henry Grant		United Farmers of Ontario	Sought re-election upon appointment as Minister of Education	Yes

† Won by acclamation

14th Legislative Assembly of Ontario 1914–1919

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Ontario North	February 18, 1919	William Hoyle		Conservative	John Wesley Widdifield		United Farmers of Ontario	Death	No
St. Catharines	February 15, 1919	Elisha Jessop		Conservative	Frederick Raymond Parnell		Conservative	Death	Yes
Huron North	December 2, 1918	Armstrong Musgrove		Conservative	William Henry Fraser		Liberal	Resignation upon appointment as Postmaster of Wingham	No
Manitoulin	October 24, 1918	Robert Roswell Gamey		Conservative	Beniah Bowman		United Farmers of Ontario	Death	No
Oxford North	September 23, 1918†	Newton Wesley Rowell		Liberal	John Alexander Calder		Liberal	Resigned to run in the 1917 federal election.	Yes
Lennox	August 29, 1918†	Thomas George Carscallen		Conservative	Reginald Amherst Fowler		Conservative	Death	Yes
York East	August 19, 1918	George Stewart Henry		Conservative	George Stewart Henry		Conservative	Sought re-election upon appointment as Minister of Agriculture		Yes
Toronto Northeast A	August 19, 1918	Robert Allan Pyne		Conservative	Henry John Cody		Conservative	Resigned to accept position as Clerk of York County.	Yes
Toronto Northwest B	January 22, 1917	William David McPherson		Conservative	William David McPherson		Conservative	Sought re-election upon appointment as Provincial Secretary and Registrar	Yes
Simcoe West	January 15, 1917†	James Stoddart Duff		Conservative	William Torrance Allen		Conservative	Death	Yes
Toronto Southwest A	August 21, 1916	James Joseph Foy		Conservative	Hartley Dewart		Liberal	Death	No
Perth North	July 10, 1916	James Torrance		Conservative	Wellington Hay		Liberal	Appointed Registrar	No
Muskoka	June 12, 1916†	Samuel Henry Armstrong		Conservative	George Walter Ecclestone		Conservative	Death	Yes
Peel	February 24, 1916	James Robinson Fallis		Conservative	William James Lowe		Liberal	Resignation	No
Algoma	October 25, 1915†	Albert Grigg		Conservative	John Morrow Robb		Conservative	Resignation upon appointment as Deputy Minister of Crown Lands	Yes
Grenville	January 7, 1915†	George Howard Ferguson		Conservative	George Howard Ferguson		Conservative	Sought re-election upon appointment as Minister of Lands, Forests and Mines	Yes
Renfrew South	January 7, 1915†	Thomas William McGarry		Conservative	Thomas William McGarry		Conservative	Sought re-election upon appointment as Provincial Treasurer	Yes
Dundas	December 7, 1914	Sir James Whitney		Conservative	Irwin Foster Hilliard		Conservative	Death	Yes
Hamilton West	November 18, 1914	John Strathearn Hendrie		Conservative	John Allan		Conservative	Appointed Lieutenant Governor of Ontario	Yes
Elgin West	October 21, 1914†	Findlay George MacDiarmid		Conservative	Findlay George MacDiarmid		Conservative	Sought re-election upon appointment as Minister of Public Works	Yes

† Won by acclamation

13th Legislative Assembly of Ontario 1911–1914

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Middlesex East	November 27, 1913	George Wesley Neely		Conservative	John McFarlane		Conservative	Death	Yes
Peel	November 3, 1913	Samuel Charters		Conservative	James Robinson Fallis		Conservative	Appointed Registrar	Yes
York East	September 8, 1913	Alexander McCowan		Conservative	George Stewart Henry		Conservative	Appointed Sheriff of York County	Yes
Grey North	July 14, 1913	Alexander Grant MacKay		Liberal	Colin Stewart Cameron		Conservative	Resignation upon entering provincial politics in Alberta	No
Grey Centre	June 2, 1913†	Isaac Benson Lucas		Conservative	Isaac Benson Lucas		Conservative	Sought re-election upon appointment as Provincial Treasurer	Yes
Lanark South	March 19, 1913	Arthur Matheson		Conservative	John Charles Ebbs		Conservative	Death	Yes
Muskoka	November 5, 1912†	Arthur Arnold Mahaffy		Conservative	Samuel Henry Armstrong		Conservative	Appointed a Judge	Yes
Waterloo North	October 28, 1912	Henry George Lackner		Conservative	Charles Henry Mills		Conservative	Appointed Sheriff of Waterloo County	Yes
Middlesex East	October 28, 1912	Robert Sutherland		Liberal	George Wesley Neely		Conservative	Death	No

† Won by acclamation

12th Legislative Assembly of Ontario 1908–1911

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Wellington South	October 21, 1910†	Joseph Patrick Downey		Conservative	John Ransom Howitt		Conservative	Appointed Superintendent for the Ontario Asylum for Idiots	Yes
Middlesex North	December 6, 1909	Duncan Campbell Ross		Liberal	James William Doyle		Conservative	Resignation to enter federal politics	No
Victoria East	May 25, 1909	John Hilliard Carnegie		Conservative	Robert Mercer Mason		Conservative	Resignation upon appointment as Distributor of Law Stamps	Yes
Algoma	December 17, 1908†	William Ross Smyth		Conservative	Albert Grigg		Conservative	Resignation to enter federal politics	Yes
Simcoe West	October 23, 1908†	James Stoddart Duff		Conservative	James Stoddart Duff		Conservative	Sought re-election upon appointment as Minister of Agriculture	Yes

† Won by acclamation

11th Legislative Assembly of Ontario 1905–1908

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Brockville	October 7, 1907	George Perry Graham		Liberal	Albert Edward Donovan		Conservative	Resignation on entering federal politics	No
Dufferin	July 24, 1907	Frederick William Lewis		Conservative	Charles Robert McKeown		Conservative	Death	Yes
York West	June 1, 1907	Joseph Wesley St. John		Conservative	Forbes Godfrey		Conservative	Death	Yes
Carleton	March 18, 1907	George Nelson Kidd		Conservative	Robert McElroy		Conservative	Death	Yes
Middlesex West	February 20, 1907	George William Ross		Liberal	Duncan Campbell Ross		Liberal	Appointed to the Senate	Yes
Hamilton East	December 4, 1906	Henry Carscallen		Conservative	Allan Studholme		Labour	Death	No
Cardwell	September 21, 1906†	Edward Alfred Little		Conservative	Alexander Ferguson		Conservative	Appointed Registrar	Yes
Toronto North	February 22, 1906	William Beattie Nesbitt		Conservative	William Kirkpatrick McNaught		Conservative	Appointed registrar of West Toronto	Yes
Kingston	January 29, 1906	Edward John Barker Pense		Liberal	Edward John Barker Pense		Liberal	Election declared void	Yes
Nipissing East	June 13, 1905†	Charles Lamarche		Conservative	Francis Cochrane		Conservative	Resignation to provide a seat for Cochrane	Yes
Toronto South	February 21, 1905†	James Joseph Foy		Conservative	James Joseph Foy		Conservative	Sought re-election upon appointment as Commissioner of Crown Lands	Yes
Toronto East	February 21, 1905†	Robert Allan Pyne		Conservative	Robert Allan Pyne		Conservative	Sought re-election upon appointment as Minister of Education	Yes
Perth South	February 21, 1905†	Samuel Nelson Monteith		Conservative	Samuel Nelson Monteith		Conservative	Sought re-election upon appointment as Minister of Agriculture	Yes
Lanark South	February 21, 1905†	Arthur James Matheson		Conservative	Arthur James Matheson		Conservative	Sought re-election upon appointment as Provincial Treasurer	Yes
Lambton West	February 21, 1905†	William John Hanna		Conservative	William John Hanna		Conservative	Sought re-election upon appointment as Provincial Secretary and Registrar	Yes
Essex North	February 21, 1905†	Joseph Octave Reaume		Conservative	Joseph Octave Reaume		Conservative	Sought re-election upon appointment as Commissioner of Public Works	Yes
Dundas	February 21, 1905†	James Pliny Whitney		Conservative	James Pliny Whitney		Conservative	Sought re-election upon appointment as Premier and Attorney-General	Yes

† Won by acclamation

10th Legislative Assembly of Ontario 1902–1904

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Oxford North	January 26, 1904	Andrew Pattulo		Liberal	James S. Munro		Liberal	Death	Yes
Renfrew North	December 26, 1903	John W. Munro		Liberal	Edward Arunah Dunlop		Conservative	Death	No
Sault Ste. Marie	October 27, 1903	Andrew Miscampbell		Conservative	Charles Napier Smith		Liberal	Void Election	No
Muskoka	October 27, 1903	Samuel Bridgeland		Liberal	Arthur Arnold Mahaffy		Conservative	Death	No
York North	February 26, 1903	Elihu James Davis		Liberal	Elihu James Davis		Liberal	Resignation in exchange for withdrawal of election petition	Yes
Bruce Centre	February 26, 1903	Hugh Clark		Conservative	Hugh Clark		Conservative	Void Election	Yes
Perth North	January 7, 1903	John C. Monteith		Conservative	John Brown		Liberal	Void Election	No
Norfolk North	January 7, 1903	Frederick S. Snider		Conservative	Archibald Little		Liberal	Void Election	No
Grey North	January 7, 1903	Alexander Grant MacKay		Liberal	Alexander Grant MacKay		Liberal	Void Election	Yes

9th Legislative Assembly of Ontario 1898–1902

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Kingston	January 30, 1902†	William Harty		Liberal	Edward John Barker Pense		Liberal	Resignation to enter federal politics	Yes
Huron West	December 4, 1901	James Thompson Garrow		Liberal	James Thompson Garrow		Liberal	Void Election	Yes
Kent East	November 4, 1901†	Robert Ferguson		Liberal	John Lee		Liberal	Death	Yes
London	July 9, 1901	Francis Baxter Leys		Liberal	Francis Baxter Leys		Liberal	Sought re-election in support of removing a dam on the Thames River	Yes
Welland	December 13, 1900	William Manley German		Liberal	John Franklin Gross		Liberal	Resignation to enter federal politics	Yes
Waterloo North	October 31, 1900†	Louis Jacob Breithaupt		Liberal	Louis Jacob Breithaupt		Liberal	Void Election	Yes
Renfrew North	June 19, 1900†	Andrew Thomas White		Conservative	John W. Munro		Liberal	Death	No
Middlesex East	January 31, 1900	Thomas D. Hodgins		Conservative	Thomas Robson		Conservative	Death	Yes
Brant South	December 12, 1899	Arthur Sturgis Hardy		Liberal	Thomas Hiram Preston		Liberal	Resignation	Yes
Elgin East	December 12, 1899	Charles Andrew Brower		Conservative	Charles Andrew Brower		Conservative	Void Election	Yes
Elgin West	December 12, 1899	Donald Macnish		Liberal	Findlay George MacDiarmid		Conservative	Void Election	No
Ontario South	December 12, 1899	John Dryden		Liberal	John Dryden		Liberal	Void Election	Yes
Renfrew South	November 14, 1899	Robert Adam Campbell		Liberal	Francis Robert Latchford		Liberal	Resignation to provide a seat for Latchford	Yes
Peterborough West	November 7, 1899†	James Robert Stratton		Liberal	James Robert Stratton		Liberal	Sought re-election upon appointment as Provincial Secretary and Registrar	Yes
Waterloo North	May 23, 1899	Henry George Lackner		Conservative	Louis Jacob Breithaupt		Liberal	Void Election	No
Perth South	February 28, 1899	William Caven Moscrip		Liberal	Samuel Nelson Monteith		Conservative	Void Election	No
Elgin West	January 12, 1899	Findlay George MacDiarmid		Conservative	Donald Macnish		Liberal	Void Election	No
Hastings North	December 27, 1898	William John Allen		Conservative	William John Allen		Conservative	Resignation in exchange for withdrawal of election petition	Yes
Nipissing	December 27, 1898	John Loughrin		Liberal	John Loughrin		Liberal	Void Election	Yes
Northumberland East	December 14, 1898	John Henry Douglas		Liberal	John Henry Douglas		Liberal	Void Election	Yes
Halton	December 8, 1898	John Roaf Barber		Liberal	John Roaf Barber		Liberal	Void Election	Yes
Huron West	December 8, 1898	James Thompson Garrow		Liberal	James Thompson Garrow		Liberal	Void Election	Yes
Lennox	November 18, 1898	Bowen Ebenezer Aylsworth		Liberal	Bowen Ebenezer Aylsworth		Liberal	Void Election	Yes
Ontario South	November 1, 1898	Charles Calder		Conservative	John Dryden		Liberal	Void Election	No
Wellington East	October 27, 1898	John Craig		Liberal	John Morison Gibson		Liberal	Death	Yes

† Won by acclamation

8th Legislative Assembly of Ontario 1894–1898

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Essex South	October 20, 1896	William Douglas Balfour		Liberal	John Allan Auld		Liberal	Death	Yes
York North	September 8, 1896†	Elihu James Davis		Liberal	Elihu James Davis		Liberal	Sought re-election upon appointment as Provincial Secretary and Registrar	Yes
Oxford North	September 7, 1896	Oliver Mowat		Liberal	Andrew Pattulo		Liberal	Appointed to the Senate	Yes
Essex South	August 4, 1896†	William Douglas Balfour		Liberal	William Douglas Balfour		Liberal	Sought re-election upon appointment as Provincial Secretary and Registrar	Yes
Wentworth South	January 24, 1896	Nicholas Awrey		Liberal	John Dickenson		Liberal	Appointed Sheriff of Wentworth County	Yes
Wellington West	January 24, 1896	George Tucker		Conservative-PPA	James Tucker		Conservative	Void Election	Yes
Kingston	October 8, 1895†	William Harty		Liberal	William Harty		Liberal	Void Election	Yes
Brant North	May 20, 1895†	William Bruce Wood		Liberal	Daniel Burt		Liberal	Resignation	Yes
Haldimand	March 19, 1895	John Senn		Conservative	Jacob Baxter		Liberal	Void Election	No
Algoma West	January 29, 1895	James M. Savage		Conservative	James Conmee		Liberal	Void Election	No
Kingston	January 28, 1895	Edward H. Smythe		Conservative	William Harty		Liberal	Void Election	No
London	November 20, 1894	William Ralph Meredith		Conservative	Thomas Saunders Hobbs		Liberal	Appointed a judge	No

† Won by acclamation

7th Legislative Assembly of Ontario 1890–1894

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Lanark South	February 16, 1894	Nathaniel McLenaghan		Conservative	James Maitland Clarke		Liberal	Resignation	No
Lambton East	December 2, 1893	Hugh McKenzie		Liberal	Peter Duncan McCallum		Independent Conservative	Death	No
Bruce North	December 2, 1893	David Porter		Liberal	Daniel McNaughton		Liberal	Death	Yes
Toronto	February 28, 1893	Nelson Gordon Bigelow		Liberal	George Ryerson		Conservative	Death	No
Peel	December 30, 1892	Kenneth Chisholm		Liberal	John Smith		Liberal	Appointed Registrar for Peel County	Yes
Toronto	April 29, 1892	Henry Edward Clarke		Conservative	Nelson Gordon Bigelow		Liberal	Death	No
Renfrew North	February 29, 1892	Arunah Dunlop		Conservative	Henry Barr		Liberal	Death	No
Kingston	February 29, 1892	James Henry Metcalfe		Conservative	William Harty		Liberal	Resignation to enter federal politics	No
Wellington East	November 10, 1891	Charles Clarke		Liberal	James Kirkwood		Liberal	Appointed Clerk of the House	Yes
Grey South	April 2, 1891†	James Hill Hunter		Liberal	Gilbert McKechnie		Liberal	Death	Yes
Bruce North	March 3, 1891	John George		Conservative	David Porter		Liberal	Void Election	No
Hamilton	February 24, 1891	Thomas Henry Stinson		Conservative	John Morison Gibson		Liberal	Void Election	No
Perth North	January 23, 1891	Alfred Emanuel Ahrens		Liberal	Thomas Magwood		Conservative	Void Election	No
Norfolk South	January 23, 1891	William Andrew Charlton		Liberal	William Andrew Charlton		Liberal	Void Election	Yes
Norfolk North	January 23, 1891	John Bailey Freeman		Liberal	Edwin Clarendon Carpenter		Liberal	Death	Yes
Durham East	January 23, 1891	George Campbell		Conservative-Equal Rights	George Campbell		Conservative-Equal Rights	Void Election	Yes
Ontario South	September 30, 1890†	John Dryden		Liberal	John Dryden		Liberal	Sought re-election upon appointment as Commissioner of Agriculture	Yes
Monck	September 30, 1890†	Richard Harcourt		Liberal	Richard Harcourt		Liberal	Sought re-election upon appointment as Provincial Treasurer	Yes

† Won by acclamation

6th Legislative Assembly of Ontario 1886–1890

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Lambton West	October 19, 1889†	Timothy Blair Pardee		Liberal	Charles MacKenzie		Liberal	Death	Yes
Hamilton	January 31, 1889†	John Morison Gibson		Liberal	John Morison Gibson		Liberal	Sought re-election upon appointment as Provincial Secretary and Registrar	Yes
Northumberland East	October 11, 1888	Richard Clarke		Liberal	William Arnson Willoughby		Conservative	Death	No
Frontenac	October 11, 1888	Henry Wilmot		Conservative	Hugh Smith		Conservative	Death	Yes
Elgin East	October 11, 1888	Thomas McIntyre Nairn		Liberal	James Charles Dance		Liberal	Death	Yes
Lanark North	October 4, 1888†	Daniel Hilliard		Liberal	William Clyde Caldwell		Liberal	Death	Yes
York North	May 23, 1888†	Joseph Henry Widdifield		Liberal	Elihu James Davis		Liberal	Resignation	Yes
Simcoe East	May 16, 1888†	Charles Alfred Drury		Liberal	Charles Alfred Drury		Liberal	Sought re-election upon appointment as Commissioner of Agriculture	Yes
Northumberland East	February 1, 1888	William Arnson Willoughby		Conservative	Richard Clarke		Liberal	Void Election	No
Dundas	January 31, 1888	Theodore F. Chamberlain		Liberal	James Pliny Whitney		Conservative	Void Election	No

† Won by acclamation

5th Legislative Assembly of Ontario 1883–1886

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Algoma East	June 29, 1885	New Seat			Robert Adam Lyon		Liberal	Algoma divided	N/A
Simcoe East	June 26, 1885	Charles Alfred Drury		Liberal	Charles Alfred Drury		Liberal	Void Election	Yes
Lennox	June 26, 1885	George Douglas Hawley		Liberal	George Douglas Hawley		Liberal	Void Election	Yes
Algoma West	June 26, 1885	New Seat			James Conmee		Liberal	Algoma divided	N/A
Kent East	June 19, 1885†	Daniel McCraney		Liberal	Robert Ferguson		Liberal	Death	Yes
Renfrew South	January 27, 1885	John Francis Dowling		Liberal	John Francis Dowling		Liberal	Void Election	Yes
Lennox	August 28, 1884	Alexander Hall Roe		Conservative	George Douglas Hawley		Liberal	Death	No
Muskoka and Parry Sound	July 23, 1884	Frederick G. Fauquier		Conservative	Jacob William Dill		Liberal	Void Election	No
Grey East	March 18, 1884	Abram William Lauder		Conservative	Neil McColman		Conservative	Death	Yes
Oxford South	March 5, 1884	Adam Crooks		Liberal	George Atwell Cooke		Liberal	Crooks declared "incurably insane" and seat vacated	Yes
Renfrew South	January 18, 1884	John Francis Dowling		Liberal	John Francis Dowling		Liberal	Void Election	Yes
Simcoe West	December 14, 1883	Orson James Phelps		Liberal	Orson James Phelps		Liberal	Void Election	Yes
Middlesex West	December 14, 1883	Alexander Johnston		Conservative	George William Ross		Liberal	Void Election	No
Cardwell	December 14, 1883	William Henry Hammell		Conservative	William Henry Hammell		Conservative	Void Election	Yes
Huron West	November 16, 1883†	Alexander McLagan Ross		Liberal	Alexander McLagan Ross		Liberal	Sought re-election upon appointment as Provincial Treasurer and Commissioner of Agriculture	Yes
Brant North	June 16, 1883	James Young		Liberal	James Young		Liberal	Sought re-election upon appointment as Provincial Treasurer and Commissioner of Agriculture	Yes

† Won by acclamation

4th Legislative Assembly of Ontario 1879–1883

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Muskoka and Parry Sound	October 30, 1882	John Classon Miller		Liberal	James Whitney Bettes		Liberal	Resignation to contest the 1882 federal election	Yes
Waterloo South	October 18, 1882	James Livingston		Liberal	Isaac Master		Liberal	Resignation to contest the 1882 federal election	Yes
Simcoe East	October 18, 1882	Herman Henry Cook		Liberal	Charles Alfred Drury		Liberal	Resignation to contest the 1882 federal election	Yes
Renfrew North	October 18, 1882†	Thomas Murray		Liberal	William Balmer McAllister		Conservative	Resignation to contest the 1882 federal election	Yes*
Hastings West	October 18, 1882	Alexander Robertson		Conservative	Baltis Rose		Conservative	Resignation to contest the 1882 federal election	Yes
Glengarry	October 18, 1882	Donald Macmaster		Conservative	James Rayside		Liberal	Resignation to contest the 1882 federal election	No
Essex South	October 18, 1882	Lewis Wigle		Conservative	William Douglas Balfour		Liberal	Resignation to contest the 1882 federal election	No
Bruce South	October 18, 1882	Rupert Mearse Wells		Liberal	Hamilton Parke O'Connor		Liberal	Resignation to contest the 1882 federal election	Yes
Peterborough West	August 24, 1881†	William Hepburn Scott		Conservative	Robert Kincaid		Conservative	Death	Yes
Durham East	June 29, 1881	John Rosevear		Conservative	Charles Herbert Brereton		Conservative	Death	Yes
Waterloo North	June 27, 1881	Moses Springer		Liberal	Elias Weber Bingeman Snider		Liberal	Resignation to become Sheriff of Waterloo County	Yes
Ontario North	June 4, 1881	Thomas Paxton		Liberal	Frank Madill		Conservative	Resignation to become Sheriff of Ontario County	No
Prescott	April 14, 1881	William Harkin		Conservative	Albert Hagar		Liberal	Death	No
Hastings West	January 30, 1880	Alexander Robertson		Conservative	Alexander Robertson		Conservative	Void Election	Yes
Stormont	January 23, 1880	Joseph Kerr		Conservative	Joseph Kerr		Conservative	Void Election	Yes
Dufferin	January 9, 1880	John Barr		Conservative	William Jelly		Conservative	Void Election	Yes

† Won by acclamation

*McAllister was a supporter of Mowat's government

3rd Legislative Assembly of Ontario 1875–1879

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Toronto East	December 21, 1878	Matthew Crooks Cameron		Conservative	Alexander Morris		Conservative	Appointed a judge	Yes
Monck	December 21, 1878	Henry Ryan Haney		Liberal	Richard Harcourt		Liberal	Death	Yes
Simcoe South	October 29, 1878	William McDougall		Independent Liberal	William James Parkhill		Conservative	Resignation to contest the 1878 federal election	No
Essex North	October 29, 1878	James Colebrooke Patterson		Conservative	Solomon White		Conservative	Resignation to contest the 1878 federal election	Yes
Elgin West	October 29, 1878	Thomas Hodgins		Liberal	David McLaws		Liberal	Resignation to contest the 1878 federal election	Yes
Algoma	October 8, 1878†	Simon James Dawson		Liberal	Robert Adam Lyon		Liberal	Resignation to contest the 1878 federal election	Yes
Brant South	March 29, 1877†	Arthur Sturgis Hardy		Liberal	Arthur Sturgis Hardy		Liberal	Sought re-election upon appointment as Provincial Secretary and Registrar	Yes
Waterloo South	February 19, 1877	John Fleming		Liberal	Isaac Master		Liberal	Death	Yes
Frontenac	February 12, 1877	Peter Graham		Conservative	Delino Dexter Calvin		Conservative	Death	Yes
Wellington South	October 11, 1876†	Peter Gow		Liberal	James Massie		Liberal	Resignation to become Sheriff of Wellington County	Yes
Northumberland East	November 9, 1875	James Marshall Ferris		Liberal	James Marshall Ferris		Liberal	Void Election	Yes
Halton	November 2, 1875	William Barber		Liberal	William Durie Lyon		Liberal	Void Election	Yes
Grey North	October 30, 1875	Thomas Scott		Conservative	David Creighton		Conservative	Void Election	Yes
Wentworth North	October 29, 1875	Thomas Stock		Conservative	James McMahon		Liberal	Void Election	No
Peterborough West	October 26, 1875	George Albertus Cox		Liberal	William Hepburn Scott		Conservative	Void Election	No
Victoria North	September 29, 1875	John David Smith		Liberal	Duncan McRae		Conservative	Void Election	No
Wellington West	September 27, 1875	John McGowan		Liberal-Conservative	John McGowan		Liberal-Conservative	Void Election	Yes
Dundas	September 25, 1875	Andrew Broder		Conservative	Andrew Broder		Conservative	Void Election	Yes
Peterborough East	September 24, 1875	John C. O'Sullivan		Conservative	John C. O'Sullivan		Conservative	Void Election	Yes
Kent East	September 17, 1875	Archibald McKellar		Liberal	Daniel McCraney		Liberal	Appointed Sheriff of Wentworth County	Yes
Essex South	September 17, 1875	Lewis Wigle		Conservative	Lewis Wigle		Conservative	Void Election	Yes
Oxford South	September 11, 1875	Adam Oliver		Liberal	Adam Crooks		Liberal	Void Election	Yes
Russell	August 12, 1875	Adam Jacob Baker		Conservative	Adam Jacob Baker		Conservative	Void Election	Yes
Victoria South	August 10, 1875	Samuel Casey Wood		Liberal	Samuel Casey Wood		Liberal	Sought re-election upon appointment as Provincial Secretary and Commissioner of Agriculture	Yes
Cornwall	July 17, 1875	Alexander Fraser McIntyre		Conservative	John Goodall Snetsinger		Liberal	Void Election	No
Welland	July 2, 1875	James Currie		Liberal	James Currie		Liberal	Void Election	Yes
Monck	June 22, 1875	Henry Ryan Haney		Liberal	Henry Ryan Haney		Liberal	Void Election	Yes
Ontario North	June 21, 1875	Thomas Paxton		Liberal	Thomas Paxton		Liberal	Void Election	Yes
Simcoe South	May 26, 1875	D'Arcy Boulton		Conservative	William McDougall		Independent Liberal	Death	No

† Won by acclamation

2nd Legislative Assembly of Ontario 1871–1874

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Peterborough West	July 30, 1874	Thomas McCulloch Fairbairn		Liberal	William Hepburn Scott		Conservative	Death	No
Wellington North	February 20, 1874	Robert McKim		Liberal	John McGowan		Conservative	Resignation to enter federal politics	No
Perth North	February 14, 1874	Andrew Monteith		Conservative	Thomas Mayne Daly		Conservative	Resignation to enter federal politics	Yes
Oxford South	January 19, 1874†	Adam Oliver		Liberal	Adam Oliver		Liberal	Resignation due to not being appointed Sheriff of Oxford County and selling timber to the provincial government	Yes
Ottawa	January 18, 1874	Richard William Scott		Liberal	Daniel John O'Donoghue		Independent Labour	Appointed to the Senate	Yes
Simcoe South	December 30, 1873	Thomas Roberts Ferguson		Conservative	D'Arcy Boulton		Conservative	Resignation	Yes
Peel	December 19, 1873	John Coyne		Conservative	Kenneth Chisholm		Liberal	Death	No
Grenville South	December 9, 1873†	Christopher Finlay Fraser		Liberal	Christopher Finlay Fraser		Liberal	Sought re-election upon appointment as Provincial Secretary and Registrar	Yes
Leeds South	December 1873†	Herbert Stone MacDonald		Conservative	John Godkin Giles		Conservative	Resignation to be appointed to the county court	Yes
Huron South	October 16, 1873	Robert Gibbons		Liberal	Archibald Bishop		Liberal	Resignation to become Sheriff of Huron County	Yes
Brant South	April 28, 1873	Edmund Burke Wood		Conservative	Arthur Sturgis Hardy		Liberal	Resignation to enter federal politics	No
Oxford North	November 29, 1872†	George Perry		Liberal	Oliver Mowat		Liberal	Resignation to provide a seat for Mowat	Yes
Lambton	November 13, 1872†	Timothy Blair Pardee		Liberal	Timothy Blair Pardee		Liberal	Sought re-election upon appointment as Provincial Secretary and Registrar	Yes
Grenville South	October 16, 1872	Christopher Finlay Fraser		Liberal	Christopher Finlay Fraser		Liberal	Void Election	Yes
Middlesex West	September 17, 1872	Alexander Mackenzie		Liberal	John Watterworth		Liberal	Resignation upon abolition of the dual mandate	Yes
Bruce South	September 14, 1872	Edward Blake		Liberal	Rupert Mearse Wells		Liberal	Resignation upon abolition of the dual mandate	Yes
Monck	September 1872	Lachlin McCallum		Conservative	Henry Ryan Haney		Liberal	Resignation upon abolition of the dual mandate	No
London	August 26, 1872	John Carling		Conservative	William Ralph Meredith		Conservative	Resignation upon abolition of the dual mandate	Yes
Lanark North	August 23, 1872	Daniel Galbraith		Liberal	William Clyde Caldwell		Liberal	Resignation to enter federal politics	Yes
Cornwall	July 13, 1872	John Sandfield Macdonald		Conservative	John Goodall Snetsinger		Liberal	Death	No
Grenville South	March 26, 1872	Mcneil Clarke		Conservative	Christopher Finlay Fraser		Liberal	Death	No
Toronto West	January 9, 1872	Adam Crooks		Liberal	Adam Crooks		Liberal	Sought re-election upon appointment as Attorney-General	Yes
Bothwell	January 6, 1872†	Archibald McKellar		Liberal	Archibald McKellar		Liberal	Sought re-election upon appointment as Commissioner of Agriculture and Public Works	Yes
Middlesex West	January 5, 1872†	Alexander Mackenzie		Liberal	Alexander Mackenzie		Liberal	Sought re-election upon appointment as Provincial Secretary and Registrar	Yes
Bruce South	January 5, 1872†	Edward Blake		Liberal	Edward Blake		Liberal	Resignation to re-contest upon being appointed Premier	Yes
Northumberland West	January 5, 1872	Alexander Fraser		Liberal	Charles Gifford		Conservative	Resignation	No
Wellington South	January 4, 1872†	Peter Gow		Liberal	Peter Gow		Liberal	Sought re-election upon appointment as Provincial Secretary and Registrar	Yes
Ottawa	January 4, 1872†	Richard William Scott		Liberal	Richard William Scott		Liberal	Sought re-election upon appointment as Commissioner of Crown Lands	Yes
Stormont	January 3, 1872	William Colquhoun		Conservative	James Bethune		Liberal	Void Election	No
Simcoe North	January 2, 1872	William Davis Ardagh		Conservative	William Davis Ardagh		Conservative	Void Election	Yes
Carleton	January 2, 1872	George William Monk		Conservative	George William Monk		Conservative	Void Election	Yes
Prince Edward	December 29, 1871	Gideon Striker		Liberal	James Simeon McCuaig		Conservative	Void Election	No
		James Simeon McCuaig		Conservative	Gideon Striker		Liberal	By-election result reversed August 29, 1872	No
Grey South	December 29, 1871	Abram William Lauder		Conservative	Abram William Lauder		Conservative	Void Election	Yes
Prescott	December 27, 1871†	George Wellesley Hamilton		Conservative	George Wellesley Hamilton		Conservative	Void Election	Yes
Durham West	December 27, 1871†	Edward Blake		Liberal	John McLeod		Liberal	Chose to sit for Bruce South	Yes

† Won by acclamation

1st Legislative Assembly of Ontario 1867–1871

By-election	Date	Incumbent	Party		Winner	Party		Cause	Retained
Prince Edward	June 29, 1870	Absalom Greeley		Liberal	William Anderson		Conservative	Appointed Sheriff of Prince Edward County	No
Renfrew North	December 1, 1869	John Supple		Conservative	Thomas Murray		Liberal	Resignation	No
Lanark South	February 3–4, 1869	William McNairn Shaw		Conservative	Abraham Code		Conservative	Death	Yes
Frontenac	October 19, 1868	Henry Smith		Conservative	Delino Dexter Calvin		Conservative	Death	Yes
Niagara	December 1867	Donald Robertson		Conservative	Stephen Richards		Conservative	Appointed Coroner	Yes

See also

• List of federal by-elections in Canada

References

Further reading

• Forman, Debra Legislators and Legislatures of Ontario: A Reference Guide. Legislative Library of Ontario Research and Information Services, 1984
• Lewis, Roderick, Centennial Edition of a History of the Electoral Districts, Legislatures and Ministries of the Province of Ontario 1867–1968. F. Fogg, Queen's Printer, 1969.
• Electoral history of Ontario: Candidates and Results. Office of the Chief Election Officer of Ontario, 1983