State Route 158 (SR 158) is a two-lane north–south state highway located in the central portion of the U.S. state of Ohio. State Route 158's southern terminus is in downtown Lancaster at its junction with U.S. Route 22, State Route 37 and State Route 188. Its northern terminus is at a T-intersection US 40 in Kirkersville. The route intersects Interstate 70 in Kirkersville, and actually follows an old alignment of Interstate 70 bypassing the town. That segment was abandoned when the Interstate was extended towards Columbus in the late 1960s.