How are political party leaders selected in Canada?

Political party leaders in Canada are selected through party leadership elections held by each party's membership. Modern Canadian party leadership elections use various forms of one-member-one-vote (OMOV) balloting, weighted point systems (such as the Conservative Party's weighted-points-per-riding system), or delegated-convention voting (rare in modern practice). Leadership elections are typically held when the previous leader resigns, retires, loses a federal election, or fails a leadership review. The outgoing leader normally remains in office until the new leader is selected.

Recent major federal leadership elections include the 2025 Liberal leadership election (March 9, 2025, which Mark Carney won against Chrystia Freeland, Karina Gould, and Frank Baylis), the 2022 Conservative leadership election (September 10, 2022, which Pierre Poilievre won decisively on the first ballot with about 70 per cent of points), the 2017 NDP leadership election (October 1, 2017, which Jagmeet Singh won on the first ballot with about 54 per cent of votes), the 2020 Conservative leadership election (August 23, 2020, which Erin O'Toole won on the third ballot against Peter MacKay), and the 2013 Liberal leadership election (April 14, 2013, which Justin Trudeau won on the first ballot with about 80 per cent of votes).

Each party sets its own rules for leadership elections. The Liberal Party uses one-member-one-vote with a weighted-point system that gives each riding 100 points, distributed proportionally based on the votes of registered Liberals in that riding (designed to give equal weight to ridings regardless of population size). The Conservative Party uses a similar weighted-point system with 100 points per riding. The NDP uses one-member-one-vote without riding weighting. The Bloc Québécois and Green Party use OMOV with various rules.

Leadership reviews are a separate mechanism. After a federal election (especially after a defeat), the party's membership typically votes on whether to confirm the existing leader at the next national convention. A leadership review can be triggered by petition (the rules vary by party). Leaders who fail leadership reviews are expected to resign and trigger a leadership election. Notable failed leadership reviews include Joe Clark's 1983 PC review (he won 66 per cent but called a leadership election anyway, lost to Brian Mulroney), Stockwell Day's 2002 Canadian Alliance review, and Erin O'Toole's 2022 Conservative review (he lost a caucus vote on February 2, 2022 and was replaced as leader). Most modern federal leaders serve about 5 to 10 years before retirement, defeat, or replacement.