| Dates of Office | Leader of the Opposition | Political Affiliation |
|---|
| 01 Jul 1867 - Mar 1873 | Vacant | |
| 06 Mar 1873 - 05 Nov 1873 | Alexander Mackenzie | Liberal |
| 06 Nov 1873 - 16 Oct 1878 | The Right Honourable Sir John A. Macdonald | Liberal Conservative |
| 17 Oct 1878 - 27 Apr 1880 | The Honourable Alexander Mackenzie | Liberal |
| 27 Apr 1880 - 04 May 1880/TD> | Vacant | |
| 04 May 1880 - 02 Jun 1887 | The Honourable Edward Blake | Liberal |
| 02 Jun 1887 - 23 Jun 1887 | Vacant | |
| 23 Jun 1887 - 10 Jul 1896 | The Honourable Wilfrid Laurier | Liberal |
| 11 Jul 1896 - 05 Feb 1901 | The Right Honourable Sir Charles Tupper | Conservative |
| 06 Feb 1901 - 09 Oct 1911 | Robert Laird Borden | Conservative |
| 10 Oct 1911 - 17 Feb 1919 | The Right Honourable Sir Wilfrid Laurier | Liberal |
| 17 Feb 1919 - 07 Aug 1919 | Daniel Duncan McKenzie (Acting) | Liberal |
| 07 Aug 1919 - 28 Dec 1921 | The Honourable William Lyon Mackenzie King | Liberal |
| 29 Dec 1921 - 28 Jun 1926 | The Right Honourable Arthur Meighen | Conservative |
| 29 Jun 1926 - 24 Sep 1926 | The Right Honourable William Lyon Mackenzie King | Liberal |
| 24 Sep 1926 - 11 Oct 1926 | Vacant | |
| 11 Oct 1926 - 11 Oct 1927 | The Honourable Hugh Guthrie (Acting) | Conservative |
| 12 Oct 1927 - 06 Aug 1930 | The Honourable Richard Bennett | Conservative |
| 07 Aug 1930 - 22 Oct 1935 | The Right Honourable William Lyon Mackenzie King | Liberal |
| 23 Oct 1935 - 06 Jul 1938 | The Right Honourable Richard Bennett | Conservative |
| 07 Jul 1938 - 13 May 1940 | The Honourable Robert James Manion | Conservative |
| 14 May 1940 - 01 Jan 1943 | The Honourable Richard Burpee Hanson (Acting) | Conservative |
| 01 Jan 1943 - 10 Jun 1945 | Gordon Graydon (Acting) | Progressive Conservative |
| 11 Jun 1945 - 20 Jul 1948 | John Bracken | Progressive Conservative |
| 20 Jul 1948 - 02 Oct 1948 | Vacant | |
| 02 Oct 1948 - 01 Nov 1954 | The Honourable George Drew | Progressive Conservative |
| 01 Nov 1954 - 01 Feb 1955 | William Rowe (Acting) | Progressive Conservative |
| 01 Feb 1955 - 01 Aug 1956 | The Honourable George Drew | Progressive Conservative |
| 01 Aug 1956 - 13 Dec 1956 | William Rowe (Acting) | Progressive Conservative |
| 14 Dec 1956 - 20 Jun 1957 | John Diefenbaker | Progressive Conservative |
| 21 Jun 1957 - 15 Jan 1958 | The Right Honourable Louis St. Laurent | Liberal |
| 16 Jan 1958 - 21 Apr 1963 | The Honourable Lester B. Pearson | Liberal |
| 22 Apr 1963 - 08 Sep 1967 | The Right Honourable John Diefenbaker | Progressive Conservative |
| 09 Sep 1967 - 05 Nov 1967 | The Honourable Michael Starr (Acting) | Progressive Conservative |
| 06 Nov 1967 - 21 Feb 1976 | The Right Honourable Robert Lorne Stanfield | Progressive Conservative |
| 22 Feb 1976 - 03 Jun 1979 | Joe Clark | Progressive Conservative |
| 04 Jun 1979 - 02 Mar 1980 | The Right Honourable Pierre Elliott Trudeau | Liberal |
| 03 Mar 1980 - 01 Feb 1983 | The Right Honourable Joe Clark | Progressive Conservative |
| 02 Feb 1983 - 28 Aug 1983 | Eric Nielson (Acting) | Progressive Conservative |
| 29 Aug 1983 - 16 Sep 1984 | The Honourable Brian Mulroney | Progressive Conservative |
| 17 Sep 1984 - 07 Feb 1990 | The Right Honourable John Turner | Liberal |
| 08 Feb 1990 - 20 Dec 1990 | The Honourable Herb Grey (Acting) | Liberal |
| 21 Dec 1990 - 24 Oct 1993 | The Honourable Jean Chrétien | Liberal |
| 25 Oct 1993 - 14 Jan 1996 | The Honourable Lucien Bouchard | Bloc Québécois |
| 15 Jan 1996 - 16 Feb 1996 | Gilles Duceppe | Bloc Québécois |
| 17 Feb 1996 - 14 Mar 1997 | Michael Gauthier | Bloc Québécois |
| 15 Mar 1997 - 01 Jun 1997 | Gilles Duceppe | Bloc Québécois |
| 02 Jun 1997 - 26 Mar 2000 | Preston Manning | Reform |
| 27 Mar 2000 - 10 Sep 2000 | Deborah Gray | Canadian Alliance |
| 11 Sep 2000 - 11 Dec 2001 | Stockwell Day | Canadian Alliance |
| 12 Dec 2001 - 20 May 2002 | John Reynolds | Canadian Alliance |
| 21 May 2002 - 08 Jan 2004 | Stephen Harper | Canadian Alliance |
| 09 Jan 2004 - 19 Mar 2004 | The Honourable Grant Hill | Conservative |
| 20 Mar 2004 - 05 Feb 2006 | The Honourable Stephen Harper | Conservative |
| 06 Feb 2006 - 01 Dec 2006 | The Honourable Bill Graham | Liberal |
| 02 Dec 2006 - 09 Dec 2008 | The Honourable Stéphane Dion | Liberal |
| 10 Dec 2008 - 01 May 2011 | The Honourable Michael Ignatieff | Liberal |
| 02 May 2011 - 22 Aug 2011 | The Honourable Jack Layton | New Democratic Party |
| 23 Aug 2011 - 23 Mar 2012 | Nycole Turmel (Acting) | New Democratic Party |
| 24 Mar 2012 - 05 Nov 2015 | The Honourable Thomas Mulcair | New Democratic Party |
| 05 Nov 2015 - 27 May 2017 | The Honourable Rona Ambrose | Conservative |
| 27 May 2017 - 24 Aug 2020 | The Honourable Andrew Scheer | Conservative |
| 24 Aug 2020 - 02 Feb 2022 | The Honourable Erin O'Toole | Conservative |
| 02 Feb 2022 - 09 Sep 2022 | The Honourable Candice Bergen (Acting) | Conservative |
| 09 Sep 2022 - 28 Apr 2025 | The Honourable Pierre Poilievre | Conservative |
| 28 Apr 2025 - 06 May 2025 | Vacant | |
| 06 May 2025 - | The Honourable Andrew Scheer | Conservative |
