By-elections to the 31st Canadian Parliament were held to fill vacancies in the House of Commons of Canada between the 1979 federal election and the 1980 federal election. The Progressive Conservative Party of Canada led a minority government for the entirety of the 31st Canadian Parliament.
Two seats became vacant during the 67-day Parliament, both were filled through by-elections.
|Prince Albert||November 19, 1979||John Diefenbaker||Progressive Conservative||Stan Hovdebo||New Democratic||Death (heart attack)||No|
|Burin—St. George's||September 19, 1979||Don Jamieson||Liberal||Roger Simmons||Liberal||Resignation||Yes|