Led by John Diefenbaker (pictured), the Progressive Conservative Party won a plurality of House of Commons seats in the Canadian federal election.

John George Diefenbaker was the 13th prime minister of Canada, serving from 1957 to 1963. He was the only Progressive Conservative party leader between 1930 and 1979 to lead the party to an election victory, doing so three times, although only once with a majority of the seats in the House of Commons.

The Progressive Conservative Party of Canada was a centre to centre-right federal political party in Canada that existed from 1942 to 2003.

A plurality vote or relative majority describes the circumstance when a party, candidate, or proposition polls more votes than any other but does not receive more than half of all votes cast.

The House of Commons of Canada is the lower house of the Parliament of Canada. Together with the Crown and the Senate of Canada, they comprise the bicameral legislature of Canada.

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, 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.