| By-election | Date | Incumbent | Party | Winner | Party | Cause | Retained |
|---|
| Yale District | December 19, 1871 | New seat | | | Charles Frederick Houghton | | Liberal | New riding as a result of British Columbia joining Confederation. | NA |
| Cariboo | December 19, 1871 | New seat | | | Joshua Spencer Thompson | | Liberal-Conservative | New riding as a result of British Columbia joining Confederation. | NA |
| Vancouver Island | December 15, 1871 | New seat | | | Robert Wallace | | Conservative | New riding as a result of British Columbia joining Confederation. | NA |
| New Westminster | December 13, 1871 | New seat | | | Hugh Nelson | | Liberal-Conservative | New riding as a result of British Columbia joining Confederation. | NA |
| Victoria | November 24, 1871 | New seat | | | Henry Nathan, Jr. andAmor De Cosmos | | Liberal | New riding as a result of British Columbia joining Confederation. Two MPs elected | NA |
| Brome | November 17, 1871 | Christopher Dunkin | | Conservative | Edward Carter | | Conservative | Appointed to the Superior Court of Quebec | Yes |
| Compton | November 11, 1871 | John Henry Pope | | Conservative | John Henry Pope | | Conservative | Recontested upon appointment as Minister of Agriculture | Yes |
| Montcalm | September 15, 1871 | Joseph Dufresne | | Conservative | Firmin Dugas | | Conservative | Appointed Sheriff of the County of St. John | Yes |
| Algoma | June 30, 1871 | Wemyss Mackenzie Simpson | | Conservative | Frederick William Cumberland | | Conservative | Appointed Indian Commissioner for the North | Yes |
| Hastings East | March 20, 1871 | Robert Read | | Conservative | John White | | Conservative | Called to the Senate | Yes |
| Provencher | March 3, 1871 | New seat | | | Pierre Delorme | | Conservative | New riding as a result of Manitoba joining Confederation. | NA |
| Selkirk | March 2, 1871 | New seat | | | Donald Alexander Smith | | Independent Conservative | New riding as a result of Manitoba joining Confederation. | NA |
| Lisgar | March 2, 1871 | New seat | | | John Christian Schultz | | Conservative | New riding as a result of Manitoba joining Confederation. | NA |
| Marquette | March 2, 1871 | New seat | | | James S. Lynch andAngus McKay | | Liberal andConservative | New riding as a result of Manitoba joining Confederation. Two MPs elected due to a tie. | NA |
| Restigouche | November 29, 1870 | William Murray Caldwell | | Liberal | George Moffat, Sr. | | Conservative | Appointed Inspector of Post Offices in New Brunswick | No |
| Richelieu | November 18, 1870 | Thomas McCarthy | | Conservative | Georges Isidore Barthe | | Independent Conservative | Death | No |
| Colchester | November 8, 1870 | Adams George Archibald | | Liberal-Conservative | Frederick M. Pearson | | Liberal | Appointed Lieutenant-Governor of Manitoba and the North-West Territories | No |
| St. Hyacinthe | September 1, 1870 | Alexandre-Édouard Kierzkowski | | Liberal | Louis Delorme | | Liberal | Death | Yes |
| Bellechasse | August 15, 1870 | Louis-Napoléon Casault | | Conservative | Télesphore Fournier | | Liberal | Appointed to Superior Court of Quebec | No |
| Quebec East | July 18, 1870 | Pierre-Gabriel Huot | | Liberal | Adolphe Guillet dit Tourangeau | | Conservative | Appointed Postmaster at Quebec | No |
| Missisquoi | July 5, 1870 | Brown Chamberlin | | Conservative | George Barnard Baker | | Liberal-Conservative | Appointed Queen's Printer | Yes |
| Kings | June 23, 1870 | William Henry Chipman | | Anti-Confederate | Leverett de Veber Chipman | | Liberal | Death | No |
| Cumberland | June 15, 1870 | Charles Tupper | | Conservative | Charles Tupper | | Conservative | Recontested upon appointment as President of the Privy Council | Yes |
| Frontenac | April 27, 1870 | Thomas Kirkpatrick | | Conservative | George Airey Kirkpatrick | | Conservative | Death | Yes |
| Brome | November 29, 1869 | Christopher Dunkin | | Conservative | Christopher Dunkin | | Conservative | Recontested upon appointment as Minister of Agriculture | Yes |
| Lanark South | November 29, 1869 | Alexander Morris | | Conservative | Alexander Morris | | Conservative | Recontested upon appointment as Minister of Inland Revenue | Yes |
| Renfrew South | November 29, 1869 | Daniel McLachlin | | Liberal | John Lorn McDougall | | Liberal | Resignation | Yes |
| Renfrew North | November 13, 1869 | John Rankin | | Liberal-Conservative | Francis Hincks | | Conservative | Resignation to provide a seat for Hincks | Yes |
| Huntingdon | October 30, 1869 | John Rose | | Liberal-Conservative | Julius Scriver | | Liberal | Resignation to move to London where he acted as the Prime Minister's unofficial representative to the UK. | No |
| Colchester | September 9, 1869 | Archibald McLelan | | Anti-Confederate | Adams George Archibald | | Liberal-Conservative | Called to the Senate | No |
| L'Islet | July 14, 1869 | Barthélemy Pouliot | | Conservative | Barthélemy Pouliot | | Conservative | Election annulled | Yes |
| Wellington Centre | July 12, 1869 | Thomas Sutherland Parker | | Liberal | James Ross | | Liberal | Death | Yes |
| Hants | April 24, 1869 | Joseph Howe | | Anti-Confederate | Joseph Howe | | Liberal-Conservative | Recontested upon appointment as President of the Privy Council | No |
| Yarmouth | April 20, 1869 | Thomas Killam | | Anti-Confederate | Frank Killam | | Liberal | Death | No |
| Richmond | April 20, 1869 | William Joseph Croke | | Anti-Confederate | Isaac LeVesconte | | Conservative | Death | No |
| Kamouraska | February 17, 1869 | Vacant | | | Charles Alphonse Pantaléon Pelletier | | Liberal | No election held in 1867 due to riots | NA |
| Northumberland | December 24, 1868 | John Mercer Johnson | | Liberal | Richard Hutchison | | Liberal | Death | Yes |
| Saint Maurice | October 30, 1868 | Louis-Léon Lesieur Desaulniers | | Conservative | Élie Lacerte | | Conservative | Appointed inspector of prisons and asylums in Quebec | Yes |
| York | October 28, 1868 | Charles Fisher | | Liberal | John Pickard | | Independent Liberal | Appointed to New Brunswick Supreme Court | No |
| Three Rivers | October 17, 1868 | Louis-Charles Boucher de Niverville | | Conservative | William McDougall | | Conservative | Appointed sheriff for the district of Trois-Rivières | Yes |
| York West | August 14, 1868 | William Pearce Howland | | Liberal-Conservative | Amos Wright | | Liberal | Appointed Lieutenant-Governor of Ontario | No |
| Montreal West | April 20, 1868 | Thomas D'Arcy McGee | | Liberal-Conservative | Michael Patrick Ryan | | Liberal-Conservative | Death (assassinated) | Yes |
| Lincoln | April 13, 1868 | James Rea Benson | | Liberal-Conservative | Thomas Rodman Merritt | | Liberal | Called to the Senate | No |
| Restigouche | March 13, 1868 | John McMillan | | Liberal | William Murray Caldwell | | Liberal | Appointed Inspector of Post Offices in New Brunswick | Yes |
| Montmorency | December 11, 1867 | Joseph-Édouard Cauchon | | Conservative | Jean Langlois | | Conservative | Called to the Senate | Yes |
| Huntingdon | November 28, 1867 | John Rose | | Liberal-Conservative | John Rose | | Liberal-Conservative | Recontested upon appointment as Minister of Finance | Yes |