Pleasant Valley is a city in Marion County, West Virginia, United States. The population was 3,506 at the 2020 census. Pleasant Valley is located at 39°27′5″N 80°8′57″W / 39.45139°N 80.14917°W. It is immediately south of the larger city and county seat of Fairmont, West Virginia. The city is also adjacent to the Tygart Valley River.