Holyhead is the largest town and a community in the county of Isle of Anglesey, Wales, with a population of 13,659 at the 2011 census.. Holyhead is on Holy Island, bounded by the Irish Sea to the north, and is separated from Anglesey island by the narrow Cymyran Strait and was originally connected to Anglesey via the Four Mile Bridge.

Saint Cybi (Welsh), or Cuby (Cornish), was a 6th-century Cornish bishop, saint, and, briefly, king, who worked largely in Cornwall and North Wales: his biography is recorded in two slightly variant medieval 'lives'.