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 shipped the wings for the Airbus A380 which were manufactured at Broughton.

Mostyn's port area is home to the headquarters of Warwick International Group Limited, manufacturers of bleach activators for detergent applications.

[4] Mostyn Hall is a large Grade I listed country house, set in extensive gardens; it lies around half a mile to the north-west of the village.

[7] A by-election was held on 31 July 2014 after the disqualification of the longstanding Independent councillor, Patrick Heesom,[8] On the 5th May 2022, as part of the most recent 2022 Welsh local elections, Mostyn elected Pamela Banks who was represented as an Independent, by a 26% majority as former councillor Patrick Heesom saw defeat.

[11] The 2011 census noted 18.2 per cent of all usual residents aged 3 years and older in the village could speak Welsh.