Pettit Lake is a large alpine lake in Blaine County, Idaho, United States, located in the Sawtooth Valley in the Sawtooth National Recreation Area.

The lake is approximately 16 miles (26 km) south of Stanley and 33 miles (53 km) northwest of Ketchum.

Pettit Lake is accessed from State Highway 75 via Sawtooth National Forest road 205.

In the southern section of the Sawtooth Valley, Pettit Lake is the third largest lake in Sawtooth National Recreation Area.

This Blaine County, Idaho state location article is a stub.