State Route 201 (SR 201) is a 22.72-mile (36.56 km) long north–south state highway in the western portion of the U.S. state of Ohio. The southern terminus of SR 201 is at an interchange with the SR 4 freeway in Dayton. Its northern terminus is at a T-intersection with SR 55 approximately 3.25 miles (5.23 km) east of Casstown.