He was returned to the Parliament of Great Britain as one of two representatives for Orford in 1784, a seat he held until 1790.[2] He later represented Totnes between 1796 and 1801.[3]
Seymour married Isabella, daughter of Reverend the Honourable George Hamilton, in 1795. Their son Sir George Hamilton Seymour was a diplomat. Seymour died on 10 March 1848, aged 84, and is buried in St. Andrew's Church, Waterloo Street Hove in Sussex[1]