List of prime ministers of Canada by time in office - wikipedia List of prime ministers of Canada by time in office William Lyon Mackenzie King was Canada 's longest serving prime minister at 21 years, 154 days, non-consecutively. Sir John A. Macdonald was Canada 's second - longest serving prime minister at 18 years, 359 days, non-consecutively. Pierre Trudeau was Canada 's third - longest serving prime minister at 15 years, 164 days, non-consecutively. Sir Wilfrid Laurier, longest consecutively serving Prime Minister Kim Campbell was Canada 's third - shortest serving prime minister at 132 days. Sir Charles Tupper was Canada 's shortest serving prime minister at 68 days. Prime ministers of Canada do not have a fixed term of office ; instead, they may stay in office as long as their government is supported by parliament under a system of responsible government. Both the number of terms served and the length of individual terms have varied considerably since Confederation. Historically, elections have been held every three to five years, although since 2006 a government act set fixed election days every four years unless parliament is dissolved earlier by the Governor General. Prime ministers can be re-elected to serve any number of consecutive mandates, and some have served up to six terms, while several others have served for less than one full term. There are also four prime ministers who served multiple non-consecutive terms in the office. Of the prime ministers who served less than one full term, two of them, Joe Clark and Paul Martin, had their time in office cut short by the collapse of a minority parliament and the subsequent election of the opposition party. In all other cases of short tenure, a new prime minister was put in place for the last few months of their predecessor 's mandate -- usually to try to gain support from the electorate before an election -- but were subsequently defeated by the opposition party. The preceding Prime Minister always stays in office during an election campaign, and that time is included in the total. The first day of a Prime Minister 's term is counted in the total, but the last day is not. This list is accurate as of January 8, 2018. Contents 1 Prime ministers 2 Footnotes 3 See also 4 References Prime ministers Liberal Party of Canada ( 10 ) Conservative Party of Canada ( 1 ) Historical conservative parties / Progressive Conservative Party of Canada ( 12 ) Prime Minister Incumbency Years in power Number of Mandates Remarks King ! William Lyon Mackenzie King 7001210000000000000 ♠ 21 years, 7002154000000000000 ♠ 154 days 1921 -- 1926, 1926 -- 1930, 1935 -- 1948 3 majority & 3 minority William Lyon Mackenzie King served for three full terms in majority governments ; two full terms in minority governments supported by opposition parties ; and one short term under a minority government cut short by the King - Byng Affair after which he was replaced by Arthur Meighen. Macdonald ! Sir John A. Macdonald 7001180000000000000 ♠ 18 years, 7002359000000000000 ♠ 359 days 1867 -- 1873, 1878 -- 1891 6 majority Sir John A. Macdonald served for four full terms in majority governments ; his second term in a majority government was cut short by the Pacific Scandal, with Alexander Mackenzie taking over ; and one term in a majority government cut short by his death, after which four others served out the end of his final term. P.E. Trudeau ! Pierre Trudeau 7001150000000000000 ♠ 15 years, 7002164000000000000 ♠ 164 days 1968 -- 1979, 1980 -- 1984 3 majority & 1 minority Pierre Trudeau served for three full terms in majority governments and one short term in a minority government. The final months of his last term were served out by John Turner. Laurier ! Sir Wilfrid Laurier 7003556300000000000 ♠ 15 years, 86 days 1896 -- 1911 4 majority Sir Wilfrid Laurier served for four full terms in majority governments. He served the longest uninterrupted term of any prime minister. Chrétien ! Jean Chrétien 7003369000000000000 ♠ 10 years, 38 days 1993 -- 2003 3 majority Jean Chrétien served for three full terms in majority governments. The final six months of his last term were served out by Paul Martin. 6 Harper ! Stephen Harper 7003355800000000000 ♠ 9 years, 271 days 2006 -- 2015 1 majority & 2 minority Stephen Harper served for two short terms in minority governments and one full term in majority government. 7 Mulroney ! Brian Mulroney 7003320300000000000 ♠ 8 years, 281 days 1984 -- 1993 2 majority Brian Mulroney served for two full terms in majority governments. The final months of his last term were served out by Kim Campbell. 8 Borden ! Sir Robert Borden 7003319600000000000 ♠ 8 years, 274 days 1911 -- 1920 2 majority Sir Robert Borden served for two full terms in majority governments. The final year and a half of his last term were served out by Arthur Meighen. 9 St. Laurent ! Louis St. Laurent 7003314000000000000 ♠ 8 years, 218 days 1948 -- 1957 2 majority Louis St. Laurent served out the end of William Lyon Mackenzie King 's last term after the latter 's retirement. He then served for two full terms in majority governments. 10 Diefenbaker ! John Diefenbaker 7003213100000000000 ♠ 5 years, 305 days 1957 -- 1963 1 majority & 2 minority John Diefenbaker served for one full term in a majority government and two short terms in minority governments. 11 Bennett ! R.B. Bennett 7003190300000000000 ♠ 5 years, 77 days 1930 -- 1935 1 majority R.B. Bennett served for one full term in a majority government. 12 Pearson ! Lester B. Pearson 7003182500000000000 ♠ 4 years, 364 days 1963 -- 1968 2 minority Lester B. Pearson served for two short terms in minority governments. The final months of his last term were served out by Pierre Trudeau. 13 Mackenzie ! Alexander Mackenzie 7003179700000000000 ♠ 4 years, 336 days 1873 -- 1878 1 majority Alexander Mackenzie took over from Sir John A. Macdonald 's first block of terms following the Pacific Scandal. He then served for one full term in a majority government. 14 J. Trudeau ! Justin Trudeau ( incumbent ) 7002796000000000000 ♠ 2 years, 65 days 2015 -- present 1 majority Justin Trudeau is currently serving his first term of office leading a majority government. 15 Martin ! Paul Martin 7002787000000000000 ♠ 2 years, 56 days 2003 -- 2006 1 minority Paul Martin served out the end of Jean Chrétien 's last term after the latter 's retirement. He then served for one short term in a minority government. 16 Thompson ! Sir John Thompson 7002737000000000000 ♠ 2 years, 7 days 1892 -- 1894 none Sir John Thompson was the second of four prime ministers to serve out the end of Sir John A. Macdonald 's last term after Macdonald 's death. He was the second, and currently last prime minister of Canada to die in office. He never won an election of his own. 17 Meighen ! Arthur Meighen 7000100000000000000 ♠ 1 year, 7002260000000000000 ♠ 260 days 1920 -- 1921, 1926 none Arthur Meighen served out the end of Sir Robert Borden 's last term after the latter 's retirement. He also briefly took over from William Lyon Mackenzie King 's second term following the King - Byng Affair. His party had won more seats than King in the 1925 election, but did not win a majority. King was able to keep governing with the support of the Progressives until defeated in a confidence vote. The Governor - General then appointed Meighen as prime minister, but his government was soon defeated in a confidence vote as well and lost the resultant 1926 federal election. 18 Abbott ! Sir John Abbott 7002527000000000000 ♠ 1 year, 161 days 1891 -- 1892 none Sir John Abbott was the first of four prime ministers to serve out the end of Sir John A. Macdonald 's last term after Macdonald 's death. Due to health reasons he did not finish the term. He never won an election of his own. 19 Bowell ! Sir Mackenzie Bowell 7002493000000000000 ♠ 1 year, 128 days 1894 -- 1896 none Sir Mackenzie Bowell was the third of four prime ministers to serve out the end of Sir John A. Macdonald 's last term after Macdonald 's death. He lost the confidence of his cabinet and resigned before the end of the term. He never won an election of his own. 20 Clark ! Joe Clark 7002273000000000000 ♠ 273 days 1979 -- 1980 1 minority Joe Clark served one short term in a minority government. 21 Campbell ! Kim Campbell 7002132000000000000 ♠ 132 days none Kim Campbell served out the end of Brian Mulroney 's last term after the latter 's retirement. She never won an election of her own. 22 Turner ! John Turner 7001790000000000000 ♠ 79 days 1984 none John Turner served out the end of Pierre Trudeau 's last term after the latter 's retirement. He never won an election of his own. He may have been one of two prime ministers who never served as a Member of Parliament or Senator during any point of his tenure as prime minister. Some sources, however, report that he was sworn in as member for Vancouver Quadra a short time before he resigned as prime minister. 23 Tupper ! Sir Charles Tupper 7001680000000000000 ♠ 68 days 1896 none Sir Charles Tupper was the fourth of four prime ministers to serve out the end of Sir John A. Macdonald 's last term after Macdonald 's death. He never won an election of his own. He was only in power during an election campaign, making him one of two prime ministers, and perhaps the only one, who never served as a Member of Parliament or Senator during any point of his tenure as prime minister. Footnotes ^ A Mackenzie King 's incumbency was in three blocks : 7003164200000000000 ♠ 4 years, 181 days ; 7003141100000000000 ♠ 3 years, 315 days ; and 7003477200000000000 ♠ 13 years, 23 days. ^ B Sir John A. Macdonald was also Premier of the Province of Canada for 250 days, giving him a total of 19 years, 244 days. ^ C Macdonald 's incumbency was in two blocks : 7003231900000000000 ♠ 6 years, 127 days and 7003461500000000000 ♠ 12 years, 232 days. ^ D The prime ministry was vacant for ten days each in 1891 and 1894. ^ E Pierre Trudeau 's incumbency was in two blocks : 7003406200000000000 ♠ 11 years, 45 days and 7003158000000000000 ♠ 4 years, 119 days. ^ F Meighen 's incumbency was in two blocks : 7002537000000000000 ♠ 1 year, 172 days and 88 days. See also Canadian politics portal List of Prime Ministers of Canada List of Canadian political parties by time in office References Jump up ^ `` 39th Parliament - 1st Session - Bill C - 16 : An Act to amend the Canada Elections Act ''. Legisinfo. Library of Parliament. December 9, 2008. Archived from the original on March 8, 2007. Retrieved March 1, 2008. Jump up ^ `` Political Information - Ministerial Experience ''. Parlinfo. Library of Parliament. September 26, 2007. Retrieved March 1, 2008. Jump up ^ Government of Canada ( 1994 ). Canada 's Prime Ministers, 1867 -- 1994 : Biographies and Anecdotes. Ottawa : National Archives of Canada. Retrieved November 28, 2008. Jump up ^ `` Jean Chrétien ''. The Canadian Who 's Who. XLIII. Toronto : University of Toronto Press. 2008. Jump up ^ `` Paul Martin ''. The Canadian Who 's Who. XLIII. Toronto : University of Toronto Press. 2008. Jump up ^ `` Stephen Harper ''. The Canadian Who 's Who. XLIII. Toronto : University of Toronto Press. 2008. Jump up ^ Donald E. Blake ( 2011 ). Two Political Worlds : Parties and Voting in British Columbia. UBC Press. ISBN 9780774843324. 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Question: who was canada's longest serving prime minister
Answer: William Lyon Mackenzie King