By-elections to the 37th Canadian Parliament were held to fill vacancies in the House of Commons of Canada between the 2000 federal election and the 2004 federal election. The Liberal Party of Canada led a majority government for the entirety of the 37th Canadian Parliament, with little change from by-elections. Sixteen seats became vacant during the life of the Parliament. Twelve of these vacancies were filled through by-elections, and four seats remained vacant when the 2004 federal election was called.