Scio is a city in Linn County, Oregon, United States. The population was 838 at the 2010 census. Oregon Geographic Names suggests that S…Scio is a city in Linn County, Oregon, United States. The population was 838 at the 2010 census. Oregon Geographic Names suggests that Scio was named by one of the original residents, William McKinney, who, with Henry L. Turner, set up a flour mill at the new town. Turner suggested McKinney come up with a name for the place, and McKinney used the name of his former home, Scio, Ohio.