The river that connects the Great Lakes to the Atlantic Ocean is the St. Lawrence River.

Quick Scoop

  • The St. Lawrence River carries water from Lake Ontario northeast through Canada toward the Gulf of St. Lawrence, which opens into the Atlantic Ocean.
  • Together with canals and locks known as the St. Lawrence Seaway, it forms a major shipping route linking inland Great Lakes ports to the ocean.

A Bit More Detail

  • The Great Lakes ultimately drain out through Lake Ontario, whose natural outlet is the St. Lawrence River, making it the primary connection between the lakes and the Atlantic.
  • The modern Great Lakes–St. Lawrence Seaway system lets large ocean-going vessels travel thousands of miles between inland cities like Chicago or Duluth and the Atlantic Ocean.

TL;DR: The St. Lawrence River is the main river that connects the Great Lakes to the Atlantic Ocean.