Leader of the New Democratic Party

The New Democratic Party was founded in 1961 following the merger of the Co-operative Commonwealth Federation (CCF) and the Canadian Labour Congress. Prior to the merger, the CCF had three leaders from its founding in 1932 until the 1961 merger, with J. S. Woodsworth serving as the CCF's first leader.^[1] Following Woodsworth's death in 1942, he was replaced by M. J. Coldwell, who led the party to their best electoral performance in 1945 by winning 28 seats.

Coldwell ended up losing his seat in the 1958 election leading to a party leadership crisis. Hazen Argue, the CCF member of Parliament for Assiniboia, was named the parliamentary leader due to Coldwell's absence from the House of Commons, however he continuously persuaded Coldwell to officially step down as leader. At the time, the CCF executives were in the process of transitioning their party into a new party with closer ties to organized labour, and wanted Tommy Douglas to become the party leader. This merger was something Argue opposed, and fearing that Argue's leadership would derail the merger, party president David Lewis tried to prevent Argue from initiating a leadership challenge during the 1960 CCF convention. This attempt was ultimately unsuccessful, and Coldwell resigned on August 10, 1960. The CCF caucus elected Argue as the new leader on the following day.

Despite the leadership crisis, the merger talks continued, and eventually culminated in the New Democratic Party founding convention in the summer of 1961. During the convention, the NDP was formally established on August 3, 1961. On the same day, Argue and Douglas ran against each other for the party leadership, with Douglas winning a landslide victory to become the first leader of the NDP. Argue left the party for the Liberals shortly afterwards.

The NDP's most successful leader was Jack Layton, who served as leader from 2004 to 2011, and led the NDP to a 103 seat result in the 2011 Canadian federal election. The NDP won the second-most seats in the House of Commons, and Layton became the first leader of the NDP to serve as the leader of the Official Opposition. However, his tenure as opposition leader was very short lived, as he died from cancer a few months later.

In the 2017 New Democratic Party leadership election, the party elected Jagmeet Singh, making him the first visible minority to lead a major Canadian federal political party.^[2] Singh, who was a member of the Ontario Provincial Parliament at the time, resigned his provincial seat and was first elected to the House of Commons on February 25, 2019 for the riding of Burnaby South.

According to the New Democratic Party's constitution, the leader of the NDP must be selected through a leadership election in-which all party members may vote.^[3] Each leadership election must use an instant-runoff voting system, where the new leader is elected once they receive 50%+1 of the votes cast in the final round of voting.

If the leadership position becomes vacant, the party's national council may appoint an interim leader until a leadership convention can be held.^[3] This has happened on two occasions, the appointment of Nycole Turmel as interim leader following the death of Jack Layton in 2011, and the appointment of Don Davies as interim leader following the resignation of Jagmeet Singh after the party's defeat in the 2025 Canadian federal election.

• History of the New Democratic Party
• New Democratic Party leadership elections
• List of Canadian conservative leaders
• Leader of the Liberal Party of Canada