State Route 185 (SR 185) is an east to west secondary highway in Gibson County, Tennessee that is 7.67 miles (12.3 km) long.

East of Dyer the highway is also called Poplar Grove Road.

It passes through downtown before turning east onto Poplar Grove Road, where it leaves Dyer and continues east through farmland before coming to an end at an intersection with SR 54.

The original western terminus was in Dyer at the intersection of Main Street (then US 45W) and Poplar Grove Road.

In 2001, when US 45W was realigned to a newly constructed bypass route to the west of Dyer, SR 185 was extended through Dyer on Main Street and Yorkville Street (formerly SR 77) to the new US 45W.