|Leader of the Official Opposition in Ontario|
|Member of||Legislative Assembly of Ontario|
|Term length||While leader of the largest party not in government|
|Inaugural holder||Edward Blake|
The Leader of the Official Opposition (French: Chef de l'opposition officielle) in Ontario, officially Leader of Her Majesty's Loyal Opposition (French: Chef de la loyale opposition de Sa Majesté), is the leader of the largest party in the Legislative Assembly of Ontario which is not part of the government. The current Leader of the Opposition is Andrea Horwath, leader of the Ontario New Democratic Party, because the NDP won the second largest number of seats as a result of the 2018 election. This is the fifth time the CCF/NDP has formed Ontario's official opposition, and the first time since the 1987 general election.
Ontario's first Leader of the Opposition was Edward Blake of the Ontario Liberal Party who held the position from 1869 until 1871 when he became Premier of Ontario (Archibald McKellar had previously led the Liberal Party in the legislature for two years, but was not formally recognized as opposition leader). Ten Leaders were Premier before after they served this post.
- Archibald McKellar (Liberal) 1867-1869 was not formally recognized as opposition leader, but led the Liberal Party in the legislature.
List of Leaders of the Official Opposition in Ontario
|#||Leader||Party||Took office||Left office|
|1.||Edward Blake||Liberal||December 1869||December 1871|
|2.||Matthew Crooks Cameron||Conservative||December 1871||1878|
|3.||William Ralph Meredith||October 1878||October 1894|
|4.||George Marter||October 1894||April 1896|
|5.||James Whitney||April 1896||January 1905|
|6.||George William Ross||Liberal||February 1905||January 1907|
|7.||George Graham||January 1907||August 1907|
|8.||Alexander Grant MacKay||August 1907||1911|
|9.||Newton Wesley Rowell||December 1911||1917|
|10.||William Proudfoot||February 1918||October 1919|
|11.||Hartley Dewart||1919||October 1921|
|12.||Wellington Hay||March 1922||June 1923|
|13.||William Sinclair 1 2||August 1923||June 1934|
|14.||George Henry||Conservative||July 1935||December 1938|
|15.||George Drew||Conservative/Progressive Conservative||1939||1943|
|16.||Ted Jolliffe||Co-operative Commonwealth Federation||August 1943||June 1945|
|17.||Farquhar Oliver||Liberal||July 1945||June 1948|
|-||Ted Jolliffe (second time)||Co-operative Commonwealth Federation||July 1948||November 1951|
|-||Farquhar Oliver3 (second time)||Liberal||1951||April 1958|
|18.||John Wintermeyer||April 1958||August 1963|
|-||Farquhar Oliver 4 (third time)||October 1963||September 1964|
|19.||Andy Thompson||September 1964||November 1966|
|20.||Robert Nixon||February 1967||September 18, 1975|
|21.||Stephen Lewis||New Democratic||October 28, 1975||April 29, 1977|
|22.||Stuart Smith||Liberal||June 1977||September 1981|
|-||Robert Nixon5 (second time)||January 25, 1982||February 21, 1982|
|23.||David Peterson||February 1982||June 1985|
|24.||Frank Miller||Progressive Conservative||1985||1985|
|26.||Bob Rae||New Democratic||1987||1990|
|-||Robert Nixon 6 (third time)||Liberal||November 20, 1990||July 31, 1991|
|27.||Murray Elston 7||1991||1991|
|28.||Jim Bradley 8||1991||1992|
|31.||Ernie Eves||Progressive Conservative||2003||2004|
|32.||Bob Runciman 9||2004||2005|
|-||Bob Runciman10 (second time)||2007||2009|
|38.||Andrea Horwath||New Democratic||2018||-|
1 The Liberals were recognized as the Official Opposition following the 1923 election by the governing Conservatives, despite the fact that the United Farmers of Ontario had more seats. According to historian Peter Oliver, this was an arbitrary decision without basis in precedent or law. Conservative Premier G. Howard Ferguson used as justification an announcement by UFO general secretary James J. Morrison that the UFO would be withdrawing from party politics, though Oliver argues that this was facetious logic. UFO parliamentary leader Manning Doherty protested the decision, but to no avail. (source: Peter Oliver, G. Howard Ferguson: Ontario Tory, (Toronto: University of Toronto Press, 1977), p. 158.)
2 From 1930, the Liberal Party was led by Mitchell Hepburn, but Sinclair continued as Leader of the Opposition as Hepburn did not seek a seat in the legislature until the 1934 general election which made him Premier.
3 Until 1954, the Liberals were led from outside the legislature by Walter Thomson with Oliver as acting Leader of the Opposition. Oliver led the party in his own right (for a second time) from 1954 until 1958.
4 Interim Liberal leader following the personal defeat of Wintermeyer in the 1963 provincial election until Thompson's election as leader.
5 Interim Liberal leader of the party following the resignation of Stuart Smith.
6 Interim Liberal leader of the party following the personal defeat of Premier David Peterson in the 1990 election.
7 Elston became interim Liberal leader when Nixon resigned from the legislature to accept a federal appointment. Elston stepped down in November when he decided to be a candidate at the Liberal leadership convention.
8 Interim Liberal leader between resignation of Elston and election of McLeod.
9 John Tory was chosen as leader of the Ontario Progressive Conservative Party on September 18, 2004, but did not hold a seat in the legislature. On September 28 the party announced that Bob Runciman would act as interim PC leader until Tory entered the legislature. Tory was elected to represent Dufferin--Peel--Wellington--Grey on March 17, 2005 and was sworn in as an MPP and leader of the opposition on March 29, 2005.
10 As Ontario PC leader John Tory did not win a seat in the 2007 election, Runciman served as Leader of the Opposition in the legislature. (Tory had been running in the Don Valley West riding.) After spending more than a year outside the legislature, Tory sought a seat in the March 5, 2009 by-election in Haliburton—Kawartha Lakes—Brock. He lost this by-election, and thereafter resigned as party leader. Runciman served as interim party leader as well as opposition leader until Hudak was chosen as the party leadership convention.
11 Wilson served as interim leader of the Progressive Conservative party following the resignation of Tim Hudak and continued to serve as Leader of the Opposition after Patrick Brown became party leader on May 9, 2015, until September when Brown won a seat in the legislature through a by-election.
12 Vic Fedeli was chosen interim leader of the PC Party by caucus on January 26, 2018, one day after Patrick Brown resigned due to allegations of sexual misconduct. He continued to serve as Leader of the Opposition after Doug Ford became party leader on March 10, 2018, as Ford did not have a seat in the legislature.
List of Deputy Leaders
|Deputy Leader||Took office||Left office||Notes|
|Sean Conway||March 9, 1982||March 25, 1985|
|September 17, 1991||December 19, 1996|
|Sandra Pupatello||June 6, 1999||September 2, 2003|
|Elizabeth Witmer||October 23, 2003||July 27, 2009|
|Christine Elliott||July 27, 2009||August 28, 2015|
|Steve Clark||September 11, 2015||May 8, 2018||Serving together|
|Sara Singh||August 23, 2018||Incumbent||Serving together|
- "McGuinty calls byelection in Tory's riding", CTV Toronto, February 4, 2009.
- "Patrick Brown elected leader of Ontario Progressive Conservatives". Toronto Sun. May 9, 2015. Retrieved May 9, 2015.