Johnson Lake is a small alpine lake in Elmore County, Idaho, United States, located in the Sawtooth Mountains in the Sawtooth National Recreation Area. The lake is accessed from Sawtooth National Forest a cutoff of trail 459 along Johnson Creek.
Johnson Lake is in the Sawtooth Wilderness, and a wilderness permit can be obtained at a registration box at trailheads or wilderness boundaries. There is one small island in the lake that is about 70 ft (21 m) long. Johnson Lake is 0.33 mi (0.53 km) downstream of The Hole.