The 40th Canadian Parliament was in session from November 18, 2008 to March 26, 2011. It was the last Parliament of the longest-running minority government in Canadian history that began with the previous Parliament. The membership of its House of Commons was determined by the results of the 2008 federal election held on October 14, 2008. Its first session was then prorogued by the Governor General on December 4, 2008, at the request of Prime Minister Stephen Harper, who was facing a likely no-confidence motion and a coalition agreement between the Liberal party and the New Democratic Party with the support of the Bloc Québécois. Of the 308 MPs elected at the October 14, 2008 general election, 64 were new to Parliament and three sat in Parliaments previous to the 39th: John Duncan, Jack Harris and Roger Pomerleau.

The 2008–2009 Canadian parliamentary dispute, during the 40th Canadian Parliament, was triggered by the expressed intention of the opposition parties to defeat the Conservative minority government on a motion of non-confidence six weeks after the federal election of October 14, 2008.