The Salish Sea, approximately 18 000 km2, is comprised of the inland marine waters of Juan de Fuca Strait, the Strait of Georgia and Puget Sound, as well as their connecting channels, passes and straits. The name recognizes the use of these waterways for thousands of years by Native people of the Northwest Coast, and is adopted in Canada and the United States (the international boundary runs the length of Juan de Fuca Strait, and Puget Sound is American territory).

Salish Sea acknowledges that these waters are considered to be one ecosystem; however, the collective term does not replace the existing place names. The entity was first proposed in 1989 but did not gain acceptance until 2009 when both federal governments and the state of Washington approved it. British Columbia adopted the name in 2010.