Johnson Mountain is a mountain summit located in the Glacier Peak Wilderness of the North Cascades in Washington state. The mountain is situated in eastern Snohomish County, in the Mt. Baker-Snoqualmie National Forest. Its nearest higher peak is White Mountain, to the northeast, along with Indian Head Peak to the east. Precipitation runoff from the mountain drains into tributaries of the Sauk River. The mountain's name honors Mackinaw Johnson, a prospector who had a cabin in the vicinity.