Canada is the largest country in the world by total area among countries with a coastline on the Atlantic Ocean.
Canada’s Atlantic frontage includes the Atlantic Ocean itself and connected marginal seas such as the Labrador Sea, Gulf of Saint Lawrence, and Hudson Bay under common geographic classifications. With approximately 9.98 million square kilometres, Canada is larger overall than Brazil, the United States, and Argentina, which also have extensive Atlantic-facing coasts.
Canada’s eastern provinces include Newfoundland and Labrador, Nova Scotia, New Brunswick, Prince Edward Island, and Quebec’s Gulf of Saint Lawrence region. The country also reaches the Arctic and Pacific oceans, making it one of the few states with coastlines on three major oceans.
Coastline classifications can vary, especially around marginal seas and enclosed bays. Even under narrower definitions that focus on Canada’s open Atlantic-facing coast, Canada remains larger than the other major Atlantic countries listed here.