By-elections to the 18th Canadian Parliament were held to fill vacancies in the House of Commons of Canada between the 1935 federal election and the 1940 federal election. The Liberal Party of Canada led a majority government for the 18th Canadian Parliament.

31 vacant seats were filled through by-elections.

By-election Date Incumbent Party Winner Party Cause Retained
Prince January 2, 1940 Alfred Edgar MacLean      Liberal James Layton Ralston      Liberal Death Yes
Saskatoon City December 18, 1939 Alexander MacGillivray Young      Liberal Walter George Brown      United Reform Movement Death No
St. James December 18, 1939 Fernand Rinfret      Liberal Eugène Durocher      Liberal Death Yes
Jacques Cartier December 18, 1939 Vital Mallette      Liberal Elphège Marier      Liberal Death Yes
Kent December 11, 1939 James Rutherford      Liberal Arthur Lisle Thompson      Liberal Death Yes
Calgary West September 18, 1939 R. B. Bennett      Conservative Douglas Cunnington      Conservative Resignation Yes
Brandon November 14, 1938 David Wilson Beaubier      Conservative James Ewen Matthews      Liberal Death No
London November 14, 1938 Frederick Cronyn Betts      Conservative Robert James Manion      Conservative Death Yes
Waterloo South November 14, 1938 Alexander Edwards      Conservative Karl Homuth      Conservative Death Yes
Cartier November 7, 1938 Samuel William Jacobs      Liberal Peter Bercovitch      Liberal Death Yes
Edmonton East March 21, 1938 William Samuel Hall      Social Credit Orvis A. Kennedy      Social Credit Death Yes
Argenteuil February 28, 1938 George H. Perley      Conservative Georges Héon      Independent Conservative Death No
St. John—Albert February 21, 1938 William Ryan      Liberal Allan McAvity      Liberal Death Yes
St. Henry January 17, 1938 Paul Mercier      Liberal Joseph Arsène Bonnier      Liberal Appointed a Circuit Court Judge of Montreal Yes
Lotbinière December 27, 1937 Joseph-Achille Verville      Liberal Joseph-Napoléon Francoeur      Liberal Death Yes
Victoria November 29, 1937 Simon Fraser Tolmie      Conservative Robert Mayhew      Liberal Death No
Dufferin—Simcoe November 8, 1937 William Earl Rowe      Conservative William Earl Rowe      Conservative Resignation Yes
Frontenac—Addington November 1, 1937 Colin Campbell      Liberal Angus Neil McCallum      Liberal Resignation Yes
Cape Breton North and Victoria October 18, 1937 Daniel Alexander Cameron      Liberal Matthew Maclean      Liberal Death Yes
Renfrew North April 5, 1937 Matthew McKay      Liberal Ralph Warren      Liberal Death Yes
Hamilton West March 22, 1937 Herbert Earl Wilton      Conservative John Allmond Marsh      Conservative Death Yes
Bonaventure March 22, 1937 Charles Marcil      Liberal Pierre-Emile Cote      Liberal Death Yes
Ottawa East October 26, 1936 Edgar-Rodolphe-Eugène Chevrier      Liberal Joseph Albert Pinard      Liberal Appointed a judge of the High Court of Justice of Ontario Yes
Gloucester August 17, 1936 Peter Veniot      Liberal Clarence Joseph Veniot      Liberal Death Yes
Wright August 3, 1936 Fizalam-William Perras      Liberal Rodolphe Leduc      Liberal Death Yes
Victoria June 8, 1936 D'Arcy Plunkett      Conservative Simon Tolmie      Conservative Death Yes
Antigonish—Guysborough March 16, 1936 William Duff      Liberal J. Ralph Kirk      Liberal Called to the Senate Yes
Portneuf January 27, 1936 Lucien Cannon      Liberal Pierre Gauthier      Liberal Appointed a Superior Court Judge of Quebec Yes
Assiniboia January 6, 1936 Robert McKenzie      Liberal James Garfield Gardiner      Liberal Resignation to provide a seat for Gardiner Yes
Queen's December 30, 1935 J. James Larabee      Liberal Charles Avery Dunning      Liberal Appointed a Fisheries Protection Officer Yes

See also