Roanoke County, Virginia. Roanoke County is a county located in the U.S. state of the Commonwealth of Virginia. As of the 2010 census, the population was 92,376. Its county seat is Salem. Roanoke County is part of the Roanoke, VA Metropolitan Statistical Area and located within the Roanoke Region of Virginia. The independent cities of Roanoke and Salem (incorporated as such in 1884 and 1968 respectively) are located within the boundaries of Roanoke County, but are not a part of the county.