Mount Baker Wilderness is a 119,989-acre (48,558 ha) wilderness area within the Mount Baker-Snoqualmie National Forest in the western Cascade Range of northern Washington state. Its eastern border is shared with the boundary of the Stephen Mather Wilderness and North Cascades National Park for a distance of 40 miles. The wilderness extends from State Route 20 north to the Canada–US border. On the west, it is bounded by the foothills of the Puget Sound lowlands.

The Mount Baker–Snoqualmie National Forest in Washington is a National Forest extending more than 140 miles (230 km) along the western slopes of the Cascade Range from the Canada–US border to the northern boundary of Mount Rainier National Park. Administered by the United States Forest Service, the forest is headquartered in Everett. There are local ranger district offices in North Bend and Skykomish.