From February 26 at 12:01 a.m. until 11:59 p.m. on February 27, there will be the statutory blackout on political advertising.

The blackout will be for the February 27 by-election being held for the Ontario Canada electoral districts of Orleans and Ottawa-Vanier.

On August 2, 2019, the Chief Electoral of Ontario received a notice of vacancy in the Legislative Assembly of Ontario for the electoral district of Ottawa-Vanier.

MPP Mona Fortier left her seat to become the Minister of Middle Class Prosperity and Associate Minister of Finance.

On September 24, 2019, a second notice of vacancy in the Legislative Assembly of Ontario was received for the electoral district of Orleans.

MPP Marie-France Lalonde resigned from her seat to run for a seat in Canadian Parliament, which she won on October 21.

On January 29, 2020, the Office of Premier Doug Ford issued writs for the byelections to be held on February 17.

Sometime before March 30, 2019, a by-election will be announced for the seat in the House of Commons representing York–Simcoe in the province of Ontario.

On October 2, the Chief Electoral Officer of Canada, Stéphane Perrault, received official notice from the Speaker of the House of Commons that the seat for York–Simcoe (Ontario) became vacant following the resignation of Peter Van Loan, who resigned on September 30. Van Loan plans to return to the practice of law, according to Bradford Today.

Under the law, the by-election date must be announced between October 12, 2018, and March 30, 2019, and will signal the start of the by-election period. According to Elections Canada, the earliest date the by-election can be held is November 19, 2018.

On December 5, Elections Canada announced a by-election for the House of Commons will be held for the seat for Chicoutimi–Le Fjord (Quebec). The seat was vacated by MP Denis Lemieux, who announced his plan to resign in November for family reasons.

On December 4, Stéphane Perrault, Acting Chief Electoral Officer of Canada, received official notice from the Speaker of the House of Commons that the seat was vacant. Canadian law requires the date of this by-election be announced between December 15, 2017, and June 2, 2018, which will signal the start of the by-election period.

On November 5, Elections Canada announced several by-elections for the House of Commons will be held on December 11. The federal by-elections will be held for the electoral districts of Battlefords–Lloydminster (Saskatchewan), Bonavista–Burin–Trinity (Newfoundland and Labrador), Scarborough–Agincourt (Ontario), and South Surrey–White Rock (British Columbia) to fill vacancies in the House of Commons.

Battlefords–Lloydminster (Saskatchewan) MP Gerry Ritz resigned on August 31 in order to retire from politics.

Bonavista–Burin–Trinity (Newfoundland and Labrador) MP Judy Foote resigned Bonavista-Burin-Trinity in September. Foote has been on leave since April for personal family medical reasons. In August, she had resigned her position as Minister of Public Services and Procurement.

The seat for Scarborough–Agincourt (Ontario) became vacant on September 14 when MP Arnold Chan died at the age of 50 of cancer after a three-year battle.

South Surrey–White Rock (British Columbia) MP Dianne Watts resigned to run for the provincial Liberal leadership.

Today, by-elections were called in Ontario, Canada, for the provincial electoral districts of Niagara Falls and Thornhill. The election for both seats will be held on February 13.

Kim Craitor resigned from his seat as MPP for Niagara Falls in September 2013. Peter Shurman resigned his assembly seat representing Thornhill last December.