By-elections to the 42nd Canadian Parliament

By-elections to the 42nd Canadian Parliament are held to fill vacancies in the House of Commons of Canada between the 2015 federal election and the 43rd Canadian federal election. The 42nd Canadian Parliament has existed since 2015 with the membership of its House of Commons having been determined by the results of the Canadian federal election held on October 19, 2015. The Liberal Party of Canada had a majority government during this Parliament.

A by-election was held on October 24, 2016, following the death of Jim Hillyer (Conservative, Medicine Hat—Cardston—Warner) on March 23, 2016.

Five by-elections were held on April 3, 2017:

One was held following the death of Mauril Bélanger (Liberal, Ottawa—Vanier) on August 16, 2016. A second was called due to the resignation from the House of Commons of former prime minister Stephen Harper (Conservative, Calgary Heritage) on August 26, 2016. A third was held due to the resignation of Jason Kenney (Conservative, Calgary Midnapore), effective September 23, 2016, in order to enter provincial politics and pursue the leadership of the Progressive Conservative Association of Alberta. A fourth by-election was called for the constituency of Markham—Thornhill following the appointment of John McCallum (Liberal) as Ambassador to China; and a fifth was called for the constituency of Saint-Laurent following the appointment of Stéphane Dion (Liberal) as Ambassador to the European Union and Ambassador to Germany. They officially resigned their seats in the House of Commons on January 31, 2017.