Field Marshal Henry Seymour Conway (1721 – 9 July 1795) was a British general and statesman. A brother of the 1st Marquess of Hertford, and cousin of Horace Walpole, he began his military career in the War of the Austrian Succession. He held various political offices including Chief Secretary for Ireland, Secretary of State for the Southern Department, Leader of the House of Commons and Secretary of State for the Northern Department. He eventually rose to the position of Commander-in-Chief of the Forces.
Conway was the second son of Francis Seymour-Conway, 1st Baron Conway (whose elder brother Popham Seymour-Conway had inherited the Conway estates) by his third wife, Charlotte Seymour-Conway (née Shorter). He entered Eton College in 1732 and from that time enjoyed a close friendship with his cousin Horace Walpole.
Conway joined the Molesworth's Regiment of Dragoons on 27 June 1737 as a lieutenant. He was transferred to the 1st Foot Guards and was promoted to captain on 14 February 1741 and to captain-lieutenant (the equivalent of lieutenant colonel) on 10 May 1742.