Mynydd Isa is a village in Flintshire, in north-east Wales. It lies between the county town of Mold, and Buckley in the community of Argoed which had a population of 5837 according to the 2011 census. Mynydd Isa was originally a small hamlet on the north side of the Mold to Buckley road just downhill from the now demolished Calvinist chapel. It did not appear on Ordnance Survey maps until 1912. Its placename is Welsh for "lowest mountain".