State Highway OSR (SH OSR) is a state highway in the U.S. state of Texas. The route is the section of the Old San Antonio Road in east-central Texas that is maintained by the Texas Department of Transportation. While most of the original Old San Antonio Road (that is, the section of the road that is not private property) follows State Highway 21, State Highway OSR provides a routing close to the original alignment of the road near and around the Bryan-College Station metropolitan area. It was originally designated on December 17, 1929, as Texas State Highway 938, with the SH OSR designation first being used in 1942.