State Route 158 (SR 158, OH 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 Interestate was extended towards Columbus in the late 1960s.

State Route 158's routing takes it through northern Fairfield County and southern Licking County. No section of State Route 158 is included as a portion of the National Highway System, a network of highways deemed most important for the nation's economy, mobility and defense.

State Route 158 was established in 1923. Its original routing utilized the majority of its current routing between Lancaster and Kirkersville. The only exception is that in Kirkersville, State Route 158 continued due north along what is now County Road 40 up to U.S. Route 40.

With the completion of Interstate 70 from Kirkersville eastward in 1959, State Route 158's northern terminus was relocated to its junction with Interstate 70. Meanwhile, for the time being, Interstate 70 followed what is now the northernmost stretch of State Route 158 to hook in with U.S. Route 40 in the western end of Kirkersville, as it would be a number of years before the Interstate would be completed along its present alignment west of State Route 158. Jurisdiction of the former stretch of the state highway north of Interstate 70 was turned over to Licking County, which renamed the roadway as County Road 40. Then, in 1969, Interstate 70 was completed along its present alignment heading west from State Route 158, and the former alignment of Interstate 70 that hooked in with U.S. Route 40 was abandoned as a freeway. Consequently, State Route 158 was restored to the north of Interstate 70, with it being the new designation for the former path of Interstate 70. This, in turn, brought the highway to its current northern terminus at U.S. Route 40 in the western end of Kirkersville.