The arrival of thousands of immigrants whose mother tongue is neither French nor English since the 1990s has not been without effect on the geography of languages in the National Capital Region. How has French evolved in the Ottawa-Gatineau region in their presence? To what extent has the fragile balance that had been built up between French and English over time been affected by their growing weight? This article seeks to answer these questions based on an analysis of the transformations in the space of French as a mother tongue over the past twenty-five years in the region. We are also interested in the new possibilities offered by the territory for the encounter between francophones and allophones, and in the capacity of the francophone community to ultimately integrate one part of the latter. The results presented in this paper point to a rather bleak future for French, especially on the Ontario side of the border.