**The tight contest in Rosemont for the October 5, 2026, Quebec National Assembly election stems from an open seat previously held by retiring independent (formerly Québec solidaire) Vincent Marissal, creating a direct matchup between Parti québécois nominee Pierre-Luc Brillant and QS candidate Gisèle Pouhe Njall.** Projections from 338Canada as of early September place the two in a near toss-up, with Brillant holding a slim edge in simulated win probabilities around 51%. Brillant, an actor and musician with prior 2022 experience in the riding and a leadership role at the Union des artistes, emphasizes sovereignty, culture, and priority reconstruction of the Maisonneuve-Rosemont hospital. Pouhe Njall, a local resident and executive director of an NGO focused on preventing sexual violence among young adults, brings community engagement on education, housing, and social issues aligned with QS priorities. Lower probabilities for Liberal David Lavoie, CAQ candidate Nour Aliyah Attié, and Conservative Mildred Mathieu align with their weaker historical and projected support in this Montreal district, where progressive and sovereigntist voters dominate. The race remains close due to potential vote splitting on the left, local turnout dynamics, and the short campaign window following the August 27 writ. Further candidate debates, local issue focus, or shifts in provincial polling could alter the balance before the September 17 nomination deadline.