Clay County er navnet på atten fylker i USA:
Clay County (Alabama) Clay County (Arkansas) Clay County (Florida) Clay County (Georgia) Clay County (Illinois) Clay County (Indiana) Clay County (Iowa) Clay County (Kansas) Clay County (Kentucky) Clay County (Minnesota) Clay County (Mississippi) Clay County (Missouri) Clay County (Nebraska) Clay County (Nord-Carolina) Clay County (Sør-Dakota) Clay County (Tennessee) Clay County (Texas) Clay County (Vest-Virginia)