Kentucky Route 422 is a short state highway in southeastern Edmonson County, Kentucky. It serves as a link between U.S. 31-W and KY 259, one of the main access roads serving the county.

KY 422 begins at an intersection with US 31W in Edmonson County, heading north on two-lane undivided Pig Road. The road passes through forested areas with some farm fields and homes. The route intersects the northern terminus of KY 743 and continues northeast through a mix of farmland and woodland with occasional residences. KY 422 comes to its northern terminus at an intersection with KY 259 in the community of Pig, where the roadway continues north as an unnumbered road to an intersection with KY 70 in Mammoth Cave National Park.

The entire route is in Edmonson County.