Saint-Hyacinthe is a city located in southwestern Quebec, Canada. It is situated east of Montreal on the Yamaska River and serves as the seat of the judicial district of the same name. The city is positioned within the Les Maskoutains Regional County Municipality in the Montérégie region.
The geography of Saint-Hyacinthe is defined by the Yamaska River, which crosses the city perpendicular to Quebec Autoroute 20. According to the 2021 Canadian census, the city has a population of 57,239 residents.