The 2021 Canadian federal election was held on September 20, 2021, to elect members of the House of Commons to the 44th Canadian Parliament. The writs of election were issued by Governor General Mary Simon on August 15, 2021, when Prime Minister Justin Trudeau requested the dissolution of parliament for a snap election.

Trudeau won a third term as prime minister, his second minority government. Though the Liberals were hoping to win a majority government in order to govern alone, the results were mostly unchanged from the 2019 Canadian federal election. The Liberals won the most seats at 160; as this fell short of the 170 seats needed for a majority in the House of Commons, they formed a minority government with support from other parties. The 2021 election set a new record for the lowest vote share for a party that would go on to form a single-party minority government. The election was the second one in a row where the Liberals succeeded in winning a plurality of seats despite having fewer votes than the Conservative Party. The Liberals won 32.6 per cent of the popular vote, while losing the popular vote to the Conservatives as they did in 2019.

The Conservatives led by Erin O'Toole won 119 seats, two fewer than their result in 2019, and continued as the Official Opposition. The Bloc Québécois led by Yves-François Blanchet won 32 seats, unchanged from the prior election. The New Democratic Party led by Jagmeet Singh won 25 seats, a net increase of one seat, but nonetheless fell short of expectations. The Green Party maintained two seats but party leader Annamie Paul was defeated for the third time in her riding of Toronto Centre. The party received 2.3 per cent of the popular vote, approximately a third of what they won in 2019. The People's Party did not win any seats, despite winning nearly 5 per cent of the popular vote, and party leader Maxime Bernier was defeated for the second time in his riding of Beauce.

Trudeau faced public blowback for holding an election in the middle of a global pandemic due to his expectation that doing so could translate his supposed rallying popularity into a landslide victory. Criticism worsened when Trudeau failed to win by a majority and instead repeated his 2019 election showing. An official government probe later found that China attempted to meddle in the election to influence Canadian foreign policy.

Paul resigned as Green Party leader two months after the election, and O'Toole was ousted as Conservative leader by his party's caucus in February 2022 over the poor showing in the election and other disagreements ongoing at the time. In March 2022, the NDP and Liberals formed a confidence and supply agreement which lasted until the NDP withdrew in September 2024.

The 2019 Canadian federal election resulted in the Liberals, led by incumbent Prime Minister Justin Trudeau, losing both their parliamentary majority and the popular vote but nevertheless winning the most seats and remaining in office as a minority government. The Conservatives, who had gained seats and won the popular vote, continued as the Official Opposition. The Bloc Québécois regained official party status and became the third party, replacing the New Democrats in that role, with the latter party losing seats but maintaining official party status as the fourth party. Although the Greens increased their seats in the House of Commons, they ultimately failed to achieve the required number of MPs (twelve) for official party status. No other party won any seats.

In the immediate aftermath of the 2019 federal election, all leaders initially announced that they would continue as the heads of their respective parties into the 43rd Canadian Parliament. Elizabeth May said that she might not lead the Greens into the 44th federal election, and ultimately resigned as Green Party leader on November 4, 2019. On November 6, 2019, the members of the Conservative caucus decided not to adopt a measure which would have given them the ability to remove Andrew Scheer as leader; his leadership would still have been reviewed at the party's next convention, which was scheduled for April 2020. On December 12, Scheer announced his intention to resign as leader. He stayed on until his successor Erin O'Toole was chosen and remains as the MP for Regina—Qu'Appelle.

On August 15, 2021, after a request from Prime Minister Trudeau, the Governor General dissolved parliament and called an election for September 20.