Kentucky Route 178 (KY 178) is a 12.200-mile-long (19.634 km) state highway in Kentucky that travels from KY 106 and KY 507 northeast of Elkton to U.S. Route 68 Business (US 68 Bus.)

It is known locally as Highland Lick Road.

KY 178 runs for a few miles in Todd County before it enters Logan County.

KY 178 reaches the orbital Russellville Bypass, which is U.S. Route 68 (US 68), US 431, and KY 80, on the west side of town.

It continues into the city and reaches its eastern terminus at the intersection with the original US 68, now signed as US 68 Business just west of the public square.