2025 Arthabaska provincial by-election

2025 Arthabaska provincial by-election

August 11, 2025

Riding of Arthabaska
Turnout59.98% ( 14.12pp)
  First party Second party
 
Candidate Alex Boissonneault Éric Duhaime
Party Parti Québécois Conservative
Popular vote 17,327 13,081
Percentage 46.37% 35.01%
Swing 36.36% 10.32%

  Third party Fourth party
 
PLQ
CAQ
Candidate Chantale Marchand Keven Brasseur
Party Liberal Coalition Avenir Québec
Popular vote 3,481 2,693
Percentage 9.32% 7.21%
Swing 5.56% 44.54%

MNA before election

Vacant

Elected MNA

Alex Boissonneault
Parti Québécois

The 2025 Arthabaska provincial by-election was held on August 11, 2025. The seat was represented by Eric Lefebvre of the CAQ until he resigned on 18 March 2025 to run for the partially-overlapping federal riding of Richmond—Arthabaska in the 2025 Canadian federal election.

In an attempt to win a seat in the National Assembly, Conservative Party of Quebec leader Éric Duhaime ran as a candidate in the by-election; he finished second behind the Parti Québécois' Alex Boissonneault. It was a recent stronghold for the Coalition Avenir Québec before Boissonneault became the first member of the Parti Québécois to be elected in the riding since 1998.