The leader of the Official Opposition () is the member of Parliament (MP) who leads the Official Opposition in Canada. This is typically the leader of the party possessing the most seats in the House of Commons that is neither the governing party nor part of a governing coalition.
Pierre Poilievre, MP for Battle RiverâÂÂCrowfoot, has been the leader of the Official Opposition since August 2025. Poilievre previously served in the role from September 2022 until April 2025, when he lost his seat in Carleton in the 2025 federal election. He was elected to his current seat in an August by-election, once again becoming leader of the Opposition.
The office should not be confused with Opposition House leader, who is a frontbencher charged with managing the business of the Opposition in the House of Commons and is formally titled Leader of the Opposition in the House of Commons. There is also a leader of the Opposition in the Senate, who is usually of the same party as the leader of the Opposition in the house.
The term leader of the opposition is used in the Parliament of Canada Act and the Standing Orders of the House of Commons, as is the term official opposition. The terms leader of the loyal opposition, his majesty's opposition, and loyal opposition are sometimes used, but are not in either the act or the standing orders. The word loyal is used to communicate the party's loyalty to monarch of Canadaas the nonpartisan personification of the nation and the state's authorityeven as its members oppose the governing party.
The leader of the Opposition is entitled to the same levels of pay and protection as a Cabinet minister and is often made a member of the King's Privy Council, generally the only non-government member of the House of Commons afforded that privilege. The leader of the Opposition is entitled to reside at the official residence of Stornoway and ranks thirteenth on the Order of Precedence, after Cabinet ministers and before lieutenant governors of the provinces. In the House of Commons seating plan, the leader of the Opposition sits directly across from the prime minister.
During the 1st Canadian Parliament, the position of the leader of the opposition was not clearly established. The Liberal Party sat on the opposition benches, but it remained a loose coalition of various interests and chose not to name a leader until becoming a more united group. Several historians note that John Sandfield Macdonald was granted the seat reserved for the Opposition leader, though he was an ally of John A. Macdonald and the two had campaigned together in the preceding election. As Sandfield Macdonald was concurrently Premier of Ontario, he did not play a major role in holding the government to account. Instead, Alexander Mackenzie emerged as a prominent opponent of the government, with some historians describing him as the de facto leader of the Opposition from 1869. Mackenzie was recognized as Leader of the Opposition in 1873, after formally assuming the leadership of the Liberal Party.
Despite its importance in the Westminster system, the role was not enshrined in law until 1905. In proposing the measure, Prime Minister Wilfrid Laurier said "the leader of the opposition under our system is just as much a part of the constitutional system of government as the Prime Minister himself." The leader was also granted a $7,000 allowance, per session, in addition to his salary as MP. According to Dean E. Henry, this "made Canada the first entity in the British Empire, probably the first in the world, to pay a state salary to an opposition leader."
Two leaders of the Opposition have died in office: Wilfrid Laurier in 1919 and Jack Layton in 2011.
The Official Opposition Shadow Cabinet in Canada is composed of members of the main opposition party and is responsible for holding the government to account and for developing and disseminating the party's policy positions. Members of the Official Opposition are generally referred to as opposition critics, but the term Shadow Minister (which is generally used in other Westminster systems) is also used.