State Route 186 is a 3.829-mile (6.162 km) state highway in Macon County. The western terminus of the route is at an interchange with Interstate 85 (I-85) approximately 9 miles (14 km) west of Auburn. The eastern terminus of the route is at its junction with US 29/US 80 approximately 8 miles (13 km) east of Tuskegee.