South Dakota Highway 36 (SD 36) is an east–west state route located in southwest South Dakota.

It begins at the junction of U.S. Route 16A on the eastern edge of Custer State Park, and ends at South Dakota Highway 79 just south of Hermosa.

From there, it travels southwest along a winding mountainous road for about 9 miles (14 km) before terminating in Custer State Park at a junction with US 16A.

At that time, it continued further west to the Wyoming border, utilizing the current route of US 16A to Custer, and U.S. Route 16 west of Custer; US 16 went northwest from Rapid City.

The western terminus was pulled back to its present location around 1935, when US 16 was rerouted southwest through the Black Hills.