The Sea-to-Sky Corridor, often referred to as the Corridor, or the Sea to Sky Country, is a region in British Columbia spreading from Horseshoe Bay through Whistler to the Pemberton Valley and sometimes beyond to include Birken and D'Arcy. From Whistler on up, the region overlaps with the older and more historic Lillooet Country, of which Squamish, at the region's centre, was once the southward extension in the days when it was the rail-port terminus from the Interior, via Lillooet, and accessible from the Lower Mainland only by sea. Most of the region is in the Squamish-Lillooet Regional District, although south of Brittania Beach a small part of the region is in the Greater Vancouver Regional District.
The term "Corridor" refers to the alignment of the region's towns along Highway 99, a.k.a. the Sea to Sky Highway, which links together the regions' three main centres - Squamish, Whistler and Pemberton. There is little development other than resource extraction outside the immediate vicinity of the highway and the towns along it, hence the linear character of the region. As with the overlap with the historical region known as Lillooet Country from Cheakamus Canyon northwards, the southern part of the region overlaps with Greater Vancouver and also with a more general and less unified but identifiable region around Howe Sound, the islands and western shore of which are respectively part of the Gulf Islands and Sunshine Coast.