Mannington is a city in Marion County, West Virginia, United States, located in the hills of North Central West Virginia. The population was 1,961 at the 2020 census. In its earliest years it was called Forks of Buffalo or Koon Town, but has been called Mannington since 1856.

U.S. Route 250 (US 250) is a United States Numbered Highway that runs from Sandusky, Ohio, to Richmond, Virginia. Within the state of West Virginia, the route runs from the Ohio border in Wheeling to the Virginia border near Thornwood.