The premierships of Pierre Trudeau occurred from April 20, 1968, to June 4, 1979, and from March 3, 1980, to June 30, 1984. Pierre Trudeau was sworn in as Prime Minister of Canada two weeks after he succeeded Prime Minister Lester B. Pearson as leader of the Liberal Party in the 1968 leadership election.
Trudeau led his Liberals to win a comfortable majority government in the subsequent 1968 federal election. In the 1972 federal election, Trudeau's Liberals were reduced to a minority government, though won a second majority in 1974. In the 1979 federal election, Trudeau's Liberals lost power to a Progressive Conservative led by Joe Clark, who formed a minority government. The PC government collapsed in a vote of non-confidence, triggering the 1980 federal election in which Trudeau's Liberals won a third majority. Trudeau is the most recent prime minister to win four elections and to serve two non-consecutive terms. His tenure of 15 years and 164 days makes him Canada's third-longest-serving prime minister, behind John A. Macdonald and William Lyon Mackenzie King.