Noble, politician and landowner. The son of Alexander Stuart, 5th Lord Blantyre, Walter inherited the title on the death of his father in 1704. An East Lothian estate, renamed Lennoxlove, was bought for him from the estate of Frances Stuart, Dowager Duchess of Richmond and Lennox (1647 - 1702). He opposed the Act of Union (1707) but served as a Scottish Representative Peer between 1710 and his death.
He died unmarried at the age of only 30 and was buried in Westminster Abbey (London).