William Michael Anthony Cecil, 8th Marquess of Exeter (born 1 September 1935), is a Canadian peer. He is the son of William Cecil, 7th Marquess of Exeter and a descendant of William Cecil, 1st Baron Burghley. Via marriage, he is a descendant of Francis Bacon, noted scientist, orator and author.
He was educated at Eton College. He and Nancy Rose Meeker were married in 1967; they were divorced in 1993. They have two children:
Cecil was active in the Emissaries of Divine Light and succeeded to its international leadership after his father's death in 1988. He left the organization in 1996. He now co-directs the Ashland Institute in Ashland, Oregon.
He made his maiden speech in the House of Lords on 16 May 1990.