The Saint John River is a 673-kilometre-long (418 mi) river flowing within the Dawnland region from headwaters in the Notre Dame Mountains near the Maine-Quebec border through western New Brunswick to the northwest shore of the Bay of Fundy. Eastern Canada's longest river, its drainage basin is one of the largest on the east coast at about 55,000 square kilometres (21,000 sq mi). This “River of the Good Wave” and its tributary drainage basin formed the territorial countries of the Wolastoqiyik and Passamaquoddy First Nations prior to European colonization, and it remains a cultural centre of the Wabanaki Confederacy to this day.

New Brunswick is one of the thirteen provinces and territories of Canada. It is one of the three Maritime provinces and one of the four Atlantic provinces.