Nathalie Sinclair Desgagné

Nathalie Sinclair-Desgagné (born 1988) is a Canadian politician who served as the member of Parliament for the riding of Terrebonne in the House of Commons from 2021 to 2025. She is a member of the Bloc Québécois.

Education and early career

Sinclair-Desgagné was born in 1988, the daughter of Bernard Sinclair-Desgagné, an economics professor at HEC Montréal, and Gilda Villaran-Calderon, an immigration lawyer.

Sinclair-Desgagné holds a degree in economics from McGill University and a master's degree from the University of Oxford. Prior to being elected, she served as a senior economic advisor to the general management of the City of Montreal. She has also worked for Deloitte and PwC.

Political career

Sinclair-Desgagné was elected to represent the riding of Terrebonne in the House of Commons in the 2021 federal election as a member of the Bloc Québécois. She served as the critic of public finances, pandemic programs and Canada Economic Development for Quebec Regions in the Bloc Québécois Shadow Cabinet.

In the 2025 federal election, the initial count completed the day after the election showed Sinclair-Desgagné losing her seat to Liberal candidate Tatiana Auguste, but Elections Canada's validation process revised the results, instead giving Sinclair-Desgagné a 44-vote victory. Because of the narrow margin, a judicial recount was automatically triggered. The recount, completed on May 10, flipped the result again, confirming Auguste as the victor by a margin of a single vote.

Sinclair-Desgagné said she would contest the result after a Bloc voter disclosed that her mail-in ballot had been returned to her due to a postal code misprint on the envelope provided by Elections Canada. After Elections Canada said that it did not have legal standing to change the result, the Bloc announced on May 15 that it would seek a court order for a new by-election. The same day, Elections Canada stated that five other mail ballots with the incorrect returning address printed had been rejected because they had arrived at the Elections Canada office in the riding after the deadline; the statement said that it could not determine if the incorrect address was responsible.

The election result was upheld on October 27 by the Superior Court of Quebec. On November 3, Sinclair-Desgagné announced that she would be appealing the ruling to the Supreme Court of Canada. On February 13, 2026, the Supreme Court annulled the result of the election in the riding, leaving the seat vacant. Auguste won the ensuing by-election on April 13 by 668 votes.

At the time of the 2025 Canadian federal election, she lived in Montreal.

Electoral record