Jacques Cartier is the first European to describe and map the Saint Lawrence River.

Jacques Cartier was a French maritime explorer from Brittany. 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 and at Hochelaga.

The St. Lawrence River is a large international river in the middle latitudes of North America connecting the Great Lakes to the North Atlantic Ocean. Its waters flow in a northeasterly direction from Lake Ontario to the Gulf of St. Lawrence, traversing Ontario and Quebec in Canada and New York in the United States. A section of the river demarcates the Canada–U.S. border.