Jacques Cartier is the first European to discover the Saint Lawrence River.

The St. Lawrence River (French: Fleuve Saint-Laurent, [flv s lo]) is a large river in the middle latitudes of North America, flowing from Lake Ontario in a roughly northeasterly direction into the Gulf of St. Lawrence, connecting the Great Lakes to the North Atlantic Ocean and forming the primary drainage outflow of the Great Lakes Basin. The river traverses the Canadian provinces of Ontario and Quebec as well as the U.S. state of New York, and is part of the international boundary between Canada and the United States. It also provides the basis for the commercial St. Lawrence Seaway.

Jacques Cartier (UK: KAR-tee-ay, also US: KAR-tee-AY, kar-TYAY, French: [ʒak kaʁtje], Quebec French: [- kaʁt͡sje]; Breton: Jakez Karter; 31 December 1491 – 1 September 1557) was a French-Breton maritime explorer for France. Jacques Cartier was the first European to describe and map the Gulf of Saint Lawrence and the shores of the Saint Lawrence River, which he named "The Country of Canadas" after the Iroquoian names for the two big settlements he saw at Stadacona (Quebec City) and at Hochelaga (Montreal Island).