The Selkirk Mountains are a mountain range spanning the northern portion of the Idaho Panhandle, eastern Washington, and southeastern British Columbia. They begin at Mica Peak near Coeur d'Alene, Idaho and extend approximately 320 km north (200 miles) from the border. The range is bounded on its west, northeast and at its northern extremity by the Columbia River. From the Columbia's confluence with the Beaver River, they are bounded on their east by the Purcell Trench, which contains the Beaver River, Duncan River, Duncan Lake, Kootenay Lake and the Kootenay River. The Selkirks are distinct from, and geologically older than, the Rocky Mountains. Together with the neighbouring Monashee and Purcell Mountains, and sometimes including the Cariboo Mountains to the northwest, the Selkirks are part of a larger grouping known as the Columbia Mountains. A scenic highway loop, the International Selkirk Loop, encircles the southern portions of the mountain range.

The Selkirks were named after Thomas Douglas, 5th Earl of Selkirk