Mount Waddington, once known as Mystery Mountain, is the highest peak in the Coast Mountains of British Columbia, Canada. Although it is lower than Mount Fairweather and Mount Quincy Adams, which straddle the United States border between Alaska and British Columbia, Mount Waddington is the highest peak that lies entirely within British Columbia. It and the subrange which surround it, known as the Waddington Range, stand at the heart of the Pacific Ranges, a remote and extremely rugged set of mountains and river valleys.

The Pacific Ranges are the southernmost subdivision of the Coast Mountains portion of the Pacific Cordillera. Located entirely within British Columbia, Canada, they run northwest from the lower stretches of the Fraser River to Bella Coola and Burke Channel, north of which are the Kitimat Ranges. The Coast Mountains lie between the Interior Plateau and the Coast of British Columbia.