On March 4, a federal by-election will be held in the electoral district of Durham (Ontario) to fill a vacancy in the House of Commons.

On August 3, 2023, the Chief Electoral Officer of Canada, Stéphane Perrault, received official notice from the Speaker of the House of Commons that Member of Parliament Erin O’Toole’s seat was vacant.

O’Toole had resigned from the seat after being removed as leader of the Conservative Party earlier in 2023.

The date for the election was not announced until January 28, which signaled the start of the by-election period.