Trois-Rivières (Three Rivers), founded in 1634, was known long before its foundation. It was Jacques Cartier, the first Frenchman, who landed in Trois-Rivières’ territory during his second voyage, in 1535. He planted a cross on Île Saint-Quentin, declaring this territory 'French'. At the time of his visit, the St. Lawrence Iroquoians inhabited the area. Unfortunately, little is known about this people, as they disappeared by the time the French returned in the 17th century.

Before the arrival of Europeans, Indigenous peoples already visited the Saint-Maurice River region, then called Metaberoutin in Atikamekw. This included the Atikamekw to the north, the Anishinaabe to the west, and the Abenaki from the south, who came to trade there. Occasionally present as well were the Innu and the Wendat, who came to exchange goods with one another.

It is said that it was at the request of the Innu chief Capitanal that the French came to establish a fort at the site known as Trois-Rivières to protect commerce.