Monarch Mountain is one of the principal summits of the Pacific Ranges subdivision of the Coast Mountains in southern British Columbia. It stands just east of a pass between the Klinaklini River and the south branch of the Atnarko River, which is a tributary of the Bella Coola River. Surrounding Monarch Mountain is the Monarch Icefield, the northernmost of the major icefields of the Pacific Ranges, and just south of it is the Ha-Iltzuk Icefield, which is the largest. Monarch is in the southern end of Tweedsmuir South Provincial Park.
The first ascent of the mountain was made on 16 July 1936 by Henry Snow Hall Jr. and Hans Fuhrer.
The summit of Monarch Mountain has an ice cap climate (EF).