Mostyn Colliery was a coal mine in Flintshire, North Wales, that was owned in the later part of its operating life by the influential Mostyn family. The colliery was located at Mostyn on the banks of the River Dee.

Mostyn is a village and community in Flintshire, Wales, and electoral ward lying on the estuary of the River Dee, located near the town of Holywell. It has a privately owned port that has in the past had a colliery and ironworks and was involved in the export of commodities, and in present times services the offshore wind industry and ships the wings for the Airbus A380 which are manufactured at Broughton.