| By-election | Date | Incumbent | Party | Winner | Party | Cause | Retained |
|---|
| Dorchester | January 27, 1917 | Albert Sévigny | | Conservative | Albert Sévigny | | Conservative | Recontested upon appointment as Minister of Inland Revenue | Yes |
| Toronto East | December 14, 1916 | Albert Edward Kemp | | Conservative | Albert Edward Kemp | | Conservative | Recontested upon appointment as Minister of Militia and Defence | Yes |
| Hochelaga | October 15, 1915 | Louis Coderre | | Conservative | Esioff-Léon Patenaude | | Conservative | Appointed a judge of the Superior Court of Quebec | Yes |
| Terrebonne | February 8, 1915 | Wilfrid Bruno Nantel | | Conservative | Gédéon Rochon | | Conservative | Appointed a Railway Commissioner | Yes |
| Westmorland | February 1, 1915 | Henry Emmerson | | Liberal | Arthur Bliss Copp | | Liberal | Death | Yes |
| Jacques Cartier | February 1, 1915 | Frederick D. Monk | | Conservative | Joseph Adélard DesCarries | | Conservative | Resignation (ill health) | Yes |
| Prince Albert | February 1, 1915 | James McKay | | Conservative | Samuel James Donaldson | | Conservative | Appointed a judge of the Supreme Court of Saskatchewan | Yes |
| London | February 1, 1915 | Thomas Beattie | | Conservative | William Gray | | Conservative | Death | Yes |
| Waterloo South | February 1, 1915 | George Adam Clare | | Conservative | Frank Stewart Scott | | Conservative | Death | Yes |
| Champlain | November 7, 1914 | Pierre Édouard Blondin | | Conservative | Pierre Édouard Blondin | | Conservative | Recontested upon appointment as Minister of Inland Revenue | Yes |
| Quebec County | November 7, 1914 | Louis-Philippe Pelletier | | Conservative | Thomas Chase-Casgrain | | Conservative | Resignation prior to being appointed a judge | Yes |
| York | December 31, 1913 | Oswald Smith Crocket | | Conservative | Harry Fulton McLeod | | Conservative | Appointed a judge of the Supreme Court of New Brunswick | Yes |
| Lanark South | December 13, 1913 | John Graham Haggart | | Conservative | Adelbert Edward Hanna | | Conservative | Death | Yes |
| Macdonald | December 13, 1913 | Alexander Morrison | | Conservative | Alexander Morrison | | Conservative | Election declared void | Yes |
| Bruce South | October 30, 1913 | James J. Donnelly | | Conservative | Reuben Eldridge Truax | | Liberal | Called to the Senate | No |
| Middlesex East | October 21, 1913 | Peter Elson | | Conservative | Samuel Francis Glass | | Conservative | Death | Yes |
| Châteauguay | October 11, 1913 | James Pollock Brown | | Liberal | James Morris | | Conservative | Death | No |
| Portage la Prairie | July 19, 1913 | Arthur Meighen | | Conservative | Arthur Meighen | | Conservative | Recontested upon appointment as Solicitor General | Yes |
| Hochelaga | November 19, 1912 | Louis Coderre | | Conservative | Louis Coderre | | Conservative | Recontested upon appointment as Secretary of State for Canada | Yes |
| Carleton | October 30, 1912 | Edward Kidd | | Conservative | William Foster Garland | | Conservative | Death | Yes |
| Richelieu | October 24, 1912 | Arthur Cardin | | Liberal | Arthur Cardin | | Liberal | Election declared void | Yes |
| Macdonald | October 12, 1912 | William D. Staples | | Conservative | Alexander Morrison | | Conservative | Appointed Grain Commissioner for Canada | Yes |
| Simcoe South | June 10, 1912 | Haughton Lennox | | Conservative | William Alves Boys | | Conservative | Appointed a judge | Yes |
| Kootenay | May 30, 1912 | Arthur Samuel Goodeve | | Conservative | Robert Francis Green | | Conservative | Appointed a Railway Commissioner | Yes |
| Renfrew South | February 22, 1912 | Thomas Andrew Low | | Liberal | George Perry Graham | | Liberal | Resignation | Yes |
| Nipissing | November 8, 1911 | George Gordon | | Conservative | Francis Cochrane | | Conservative | Called to the Senate | Yes |
| Leeds | November 6, 1911 | George Taylor | | Conservative | William Thomas White | | Conservative | Called to the Senate | Yes |
| Yale—Cariboo | November 4, 1911 | Martin Burrell | | Conservative | Martin Burrell | | Conservative | Recontested upon appointment as Minister of Agriculture | Yes |
| Halifax | October 27, 1911 | Robert Borden | | Conservative | Robert Borden | | Conservative | Recontested upon appointment as Prime Minister | Yes |
| Elgin West | October 27, 1911 | Thomas Wilson Crothers | | Conservative | Thomas Wilson Crothers | | Conservative | Recontested upon appointment as Minister of Labour | Yes |
| St. Anne | October 27, 1911 | Charles Doherty | | Conservative | Charles Doherty | | Conservative | Recontested upon appointment as Minister of Justice | Yes |
| Toronto North | October 27, 1911 | George Eulas Foster | | Conservative | George Eulas Foster | | Conservative | Recontested upon appointment as Minister of Trade and Commerce | Yes |
| City and County of St. John | October 27, 1911 | John Waterhouse Daniel | | Conservative | John Douglas Hazen | | Conservative | Resignation to provide a seat for Hazen | Yes |
| Victoria | October 27, 1911 | Sam Hughes | | Liberal-Conservative | Sam Hughes | | Liberal-Conservative | Recontested upon appointment as Minister of Militia and Defence | Yes |
| Jacques Cartier | October 27, 1911 | Frederick Debartzch Monk | | Conservative | Frederick Debartzch Monk | | Conservative | Recontested upon appointment as Minister of Public Works | Yes |
| Terrebonne | October 27, 1911 | Wilfrid Bruno Nantel | | Conservative | Wilfrid Bruno Nantel | | Conservative | Recontested upon appointment as Minister of Inland Revenue | Yes |
| Quebec County | October 27, 1911 | Louis-Philippe Pelletier | | Conservative | Louis-Philippe Pelletier | | Conservative | Recontested upon appointment as Postmaster-General | Yes |
| Grenville | October 27, 1911 | John Dowsley Reid | | Conservative | John Dowsley Reid | | Conservative | Recontested upon appointment as Minister of Customs | Yes |
| Marquette | October 27, 1911 | William James Roche | | Conservative | William James Roche | | Conservative | Recontested upon appointment as Secretary of State for Canada | Yes |
| Winnipeg | October 27, 1911 | Alexander Haggart | | Conservative | Robert Rogers | | Conservative | Resignation to provide a seat for Rogers | Yes |