Joseph Philippe Pierre Yves Elliott Trudeau, PC, CC, CH, QC, MSRC (October 18, 1919 – September 28, 2000), usually known as Pierre Trudeau or Pierre Elliott Trudeau, was the 15th Prime Minister of Canada from 20 April 1968 to 4 June 1979, and again from 3 March 1980 to 30 June 1984.

Trudeau began his political career campaigning for socialist ideals, but he eventually joined the Liberal Party when he entered federal politics in the 1960s. He was appointed as Lester Pearson's parliamentary secretary, and later became his Minister of Justice. From his base in Montreal, Trudeau took control of the Liberal Party and became a charismatic leader, inspiring "Trudeaumania". From the late 1960s until the mid-1980s, he dominated the Canadian political scene and aroused passionate reactions. "Reason before passion" was his personal motto. He retired from politics in 1984 and was replaced by John Turner.

Admirers praise the force of Trudeau's intellect and they salute his political acumen in preserving national unity against Quebec separatists, suppressing a violent revolt, and establishing the Charter of Rights and Freedoms within Canada's constitution. His detractors accuse him of arrogance, economic mismanagement, and unduly favouring the authority of the federal government in relation to the provinces, especially in trying to control the oil wealth of the Prairies.