The British Columbia Coast is one of Canada's two continental coastlines; the other being the coastline from the Beaufort Sea of the Arctic Ocean via the Northwest Passage and Hudson Bay to the Ungava Peninsula and Labrador and the Gulf of St. Lawrence to the Bay of Fundy to the international border of New Brunswick and Maine at Passamaquoddy Bay.

The British Columbia Coast is a temperate rain forest, within the Pacific temperate rain forest region.

In a sense excluding the urban Lower Mainland area adjacent to the American border, which is considered "The Coast," the British Columbia Coast refers to one of BC's three main regions, the others being the Lower Mainland and The Interior. In the Interior, "down on the Coast" generally refers, however, to being in the Lower Mainland or Greater Victoria, while "out on the Coast" could mean in Prince Rupert or Port Hardy, on the North Coast and northern Vancouver Island respectively, which are only some of the vast coastal region's many distinct subareas.

Although fully totalling 965 km in aerial-distance length from Victoria on the Strait of Juan de Fuca to Stewart, British Columbia on the Alaska border at the head of the Portland Canal, its aerial length is usually considered as the 840 km that from the 49th Parallel in the Strait of Georgia to 54'40", which is the southern limit of the Alaska Panhandle (see Oregon boundary dispute).

However, because of its many deep inlets and complicated island shorelines - and 40,000 islands of varying sizes, including Vancouver Island and the Queen Charlotte Islands (now properly known as Haida Gwaii, Land of the Haida), the total length of the British Columbia Coast is 25,000 km - much longer than the entire rest of the Canadian coastline at 20,000 km, even including the island of Newfoundland and the Canadian Arctic Archipelago. This is known as the coastline paradox.

The coastline's geography is most comparable to that of Norway and its heavily-indented coastline of fjords. The inland straits, the Strait of Georgia in particular, share coastal affinities with the semi-inland waters of Oslofjord and its shoreline archipelago and similarly with the waters around Trondheimsfjord farther north. North from there the mainland coast resembles the great fjords of Geirangerfjord, Hardangerfjord, Sognefjord and the rest of the western and northern Norwegian coastline.