Lord Robert Seymour (20 January 1748 – 23 November 1831) was a British politician, the third son of Francis Seymour-Conway, 1st Marquess of Hertford. He was known as Hon. Robert Seymour-Conway until 1793, when his father was created a marquess; he then became Lord Robert Seymour-Conway, but dropped the surname of Conway after his father's death in 1794.
Educated at Eton, he was commissioned an ensign in the 40th Regiment of Foot in 1766, and became a lieutenant in the 2nd Regiment of Irish Horse the same year. In 1770, he became a captain in the 8th Dragoons.
Seymour-Conway was returned for two Parliamentary seats in 1771: Lisburn, in the Parliament of Ireland, and the family borough of Orford in the British House of Commons. In 1773, he became a major in the 3rd Irish Horse.
By his first marriage, on 15 June 1773 to Anne Delmé, daughter of MP Peter Delmé, Seymour-Conway had five children:
Seymour-Conway transferred into the 1st Foot Guards as a Captain-Lieutenant on 7 November 1775, and became captain of a company in the regiment on 30 January 1776. He gave up his seat at Lisburn that year, but continued to sit for Orford. He served as an aide-de-camp to Sir Henry Clinton in America from 1780 to 1781, but resigned his commission in 1782.