The 1957 Canadian federal election was held June 10, 1957, to select the 265 members of the House of Commons of Canada of the 23rd Parliament of Canada. In one of the greatest upsets in Canadian political history, the Progressive Conservative Party (also known as "PCs" or "Tories"), led by John Diefenbaker, brought an end to 22 years of Liberal rule, as the Tories were able to form a minority government despite losing the popular vote to the Liberals.