Kentucky Route 12 (KY 12) is a State Highway located in Shelby and Franklin counties, in the northern region of the U.S. state of Kentucky. The highway is approximately 21.285 miles (34.255 km) long, and travels from an intersection with State Route 43 in Shelby County to the Franklin–Henry county line. Parts of the route have existed since circa 1939, and the rest of the highway has existed since circa 1988.

By at least 1939, the portion of highway traveling from State Route 43 to State Route 37 near the location of the present highway was designated as State Route 12. The portion of this road that traveled from KY 43 to the community of Bagdad had a graded, hard surface, the portion traveling from Bagdad to the Franklin County line was gravel surfaced, while the rest of the highway was unimproved. Between 1939 and 1941, the rest of present day Route 12 was created as a graded, unpaved road, but was not yet designated as part of the highway. The next year, the entire length of the portion of the highway in Shelby County was improved. From 1942 to 1955, the portion of highway in Shelby County underwent minor rerouted, with an overall length of 6.8 miles (10.9 km). Also by 1955, the Franklin County portion had been named Dry Ridge Road. At least two years later, the length of the highway located from the western terminus to Bagdad had been paved. Between 1957 and 1962, the Franklin County portion of the route was improved to hard surface, and the route underwent minor rerouting. By 1967, the route had been paved, and had been rerouted to more of the modern route. By at least 1988, the rest of the present-day highway had been designated and paved.