Rockville is a city in Stearns County, Minnesota, United States. The population was 2,448 as of the 2010 census. It is part of the St. Clou…Rockville is a city in Stearns County, Minnesota, United States. The population was 2,448 as of the 2010 census. It is part of the St. Cloud Metropolitan Statistical Area. According to the local oral tradition, a village of the Dakota people was once located to the north of the lake.