Clay is the county seat of Clay County, West Virginia, USA. The population was 593 at the 2000 census. It is the only incorporated town in the county. Clay was established on the site of a farm that was the site of Clay County's first court meeting following the county's establishment in 1858. The community was initially known by the name of "Marshall," then briefly as "Henry," and then as "Clay Courthouse" and finally Clay. The town and county are both named for U.S. Senator and Secretary of State Henry Clay(1777–1852).