Mold is a town and community in Flintshire, Wales, on the River Alyn. It is the county town and administrative seat of Flintshire County Council, …Mold is a town and community in Flintshire, Wales, on the River Alyn. It is the county town and administrative seat of Flintshire County Council, as it was of Clwyd from 1974 to 1996. According to the 2011 UK census, it had a population of 10,058. A 2019 estimate puts it at 10,123.