State Route 46 is a north–south state highway in the northeastern portion of the U.S. state of Ohio. Its southern terminus is at State Route 170 in East Palestine (this point is also the eastern terminus of State Route 558), and its northern terminus is at State Route 11 several miles south of State Route 531 in Plymouth Township. In its northernmost portion, from south of Ashtabula to Cortland, Route 46 is a 2-lane highway while running parallel within a few miles to limited-access State Route 11 to the east.