Alfred Dillwyn "Dilly" Knox, CMG (23 July 1884 – 27 February 1943) was a British classics scholar and papyrologist at King's College, Cambridge and a codebreaker. As a member of the World War I Room 40 codebreaking unit, he helped decrypt the Zimmermann Telegram which brought the USA into the war. He joined the GC&CS at the war's end.