The Eighteenth Canadian Ministry was the cabinet chaired by Prime Minister John Diefenbaker. It governed Canada from 21 June 1957 to 22 April 1963, including all of the 23rd, 24th, and 25th Canadian Parliaments. The government was formed by the Progressive Conservative Party of Canada.

The 25th Canadian Parliament was in session from September 27, 1962, until February 6, 1963. The membership was set by the 1962 federal election on June 18, 1962, and it changed only somewhat due to resignations and by-elections until it was dissolved prior to the 1963 election.