State Route 201 (SR 201, Ohio 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 terminus is at a T-intersection with SR 55 approximately 3.25 miles (5.23 km) east of Casstown.

Along its path, SR 201 passes through the eastern portion of Montgomery County and the eastern portion of Miami County. There are segments of SR 201 that are included as a part of the National Highway System (NHS). The NHS is a network of highways that are identified as being most important for the economy, mobility and defense of the nation.

SR 201 begins in downtown Dayton, just a block from where SR 202 begins. The route starts as Valley Street in Dayton, running northward along the Mad River. SR 201 follows Valley Street until the intersection with Brandt Street, and then follows Brandt Street northward toward Riverside. After entering Riverside, Brandt Street changes its name to Brandt Pike. SR 201 continues as Brandt Pike (even as it again passes inside Dayton city limits) through Huber Heights until it reaches the unincorporated community of Brandt in Bethel Township, Miami County. From there it loses its alternative name and continues northward, ending near Casstown, at the intersection with SR 55.

The SR 201 designation was applied in 1923. It was originally routed from its southern terminus in Dayton to its junction with US 40 in Brandt. SR 201 was extended to the north in 1937, routed from US 40 in Brandt to SR 55.