Sir Roger Mostyn, 5th Baronet

Sir Roger Mostyn, 5th Baronet (13 November 1734 – 26 July 1796) was a Welsh landowner and baronet.
He was born the son of Sir Thomas Mostyn, 4th Baronet of Mostyn, Flintshire and his wife Sarah, daughter and co-heiress of Robert Western of London. He was educated at Westminster School (1745–51) and Christ Church, Oxford before succeeding his father to the baronetcy in 1758.He inherited a number of estates, including the seat at Mostyn, in both Wales and Cheshire.
He served as Lord Lieutenant and Custos Rotulorum of Flintshire from 1761 to his death and was a Lieut-Colonel in the Flintshire Militia.
He represented Flintshire in the Parliament of Great Britain from April 1758 (on the death of his father) to his own death in 1796, being elected 9 times.
He married the triple heiress Margaret, daughter and heiress of Rev. Hugh Wynn, DD, prebendary of Salisbury, and heiress of two uncles. They had 1 son and 6 daughters. He was succeeded by Sir Thomas Mostyn, 6th Baronet, who died unmarried, causing the baronetcy to become extinct.