Baron Mostyn, of Mostyn in the County of Flint, is a title in the Peerage of the United Kingdom. It was created in 1831 for Sir Edward Lloyd, 2nd Baronet, who had earlier represented Flint Boroughs and Beaumaris in the House of Commons. His son, the second Baron, sat as a Member of Parliament for Flintshire and Lichfield and served as Lord Lieutenant of Merionethshire. The holders of the barony from the 6th Baron onwards have not successfully proved their succession to the baronetcy and therefore do not appear on the Official Roll of the Baronetage (for more information follow this link).