A by-election was held in the federal riding of Mississauga—Lakeshore in Ontario on December 12, 2022, following the resignation of incumbent Liberal MP Sven Spengemann.

The Speaker's warrant regarding the vacancy was received on May 30, 2022; under the Parliament of Canada Act the writ for a by-election had to be dropped no later than November 26, 2022, 180 days after the Chief Electoral Officer was officially notified of the vacancy via a warrant issued by the Speaker.

[9] Former Conservative candidate Michael Ras, who finished second to Spengemann in 2021, considered running for the nomination before declining on social media.

[10] Running for the Green Party is Mary Kidnew, the founder of the Mississauga-Lakeshore Green Party Electoral District Association (EDA), known community advocate and a past president of the Hillcrest Ratepayers Association.

[13] The Longest Ballot Committee[14] organized a protest against the Trudeau government's abandonment of electoral reform in 2017 by running thirty-three[citation needed] independent candidates, breaking their own record for most candidates nominated in a single riding in Canada, previously set in the riding of Saint Boniface—Saint Vital in the 2021 Canadian federal election.