The Coast Mountains are a major mountain range, in the Pacific Coast Ranges, of western North America, extending from southwestern Yukon through the Alaska Panhandle and virtually all of the Coast of British Columbia south to the Fraser River. They are so-named because of their proximity to the sea coast, and are often referred to as the Coast Range. It includes volcanic and non-volcanic mountains and the huge icefields of the Pacific and Boundary Ranges, and the northern end of the notable volcanic system known as the Cascade Volcanoes. The Coast Mountains are part of a larger mountain system called the Pacific Coast Ranges or the Pacific Mountain System, which includes the Cascade Range, the Insular Mountains, the Oregon and California Coast Ranges and the Saint Elias and Chugach Mountains.

The Coast Mountains are approximately 1,600 kilometres (990 mi) long and average 300 kilometres (190 mi) in width. Its southern and southeastern boundaries are surrounded by the Fraser River and the Interior Plateau while its far northwestern edge is delimited by the Kelsall and Tatshenshini Rivers at the north end of the Alaska Panhandle, beyond which are the Saint Elias Mountains, and by Champagne Pass in the Yukon Territory. Covered in dense temperate rainforest on its western exposures, the range rises to heavily glaciated peaks, including the largest temperate-latitude icefields in the world. It then tapers to the dry Interior Plateau on its eastern flanks, or to the subarctic boreal forest of the Skeena Mountains and Stikine Plateau.

The Coastal Mountain Range, also known as the Hai'an Range (Chinese: 海岸山脈; pinyin: Hǎi'àn Shānmài), is a mountain range situated on the eastern coast of the island of Taiwan, and spans the border between Hualien and Taitung Counties. Coastal Mountain Range is part of the Philippine Mobile Belt which was formed over 400 million years ago by the collision and compression of Philippine Mobile Belt and Eurasian Plate. The geological structure is composed of soft sediments which have weaker anti-erosion property and are vulnerable to wind.

The Huatung Valley, the result of the collision of two tectonic plates, is at the west end of the range, and the tallest peak of the range is Xingangshan (新港山), which stands 1,682 m (5,518 ft) tall. Currently those peaks are still with an annual speed of 3 mm. The Haian Range is also converging with Central Mountain Range with an average speed of 2.3 cm per year.

There are several small basins located around the range, the largest of which is Taiyuan Basin.