Kentucky Route 1 (KY 1) is a 48.486-mile-long (78.031 km) state highway in the U.S. state of Kentucky. It originates at a junction with KY 3, one mile (1.6 km) east of in Lawrence County. The route continues through Grayson in Carter County to terminate at US 23 in Greenup in Greenup County. Part of the highway is co-signed with the . Segments of KY 1 are built upon the old Eastern Kentucky Railroad. KY 1 follows parts of the Little Sandy River and parts of a smaller fork of the Little Sandy called the Little Fork upstream of Grayson.