Dillwyn Knox

Alfred Dillwyn 'Dilly' Knox CMG (23 July 1884 – 27 February 1943) was a classics scholar at King's College, Cambridge, and a British codebreaker. He was a member of the World War I Room 40 codebreaking unit, and later at Bletchley Park he worked on the cryptanalysis of Enigma ciphers until his death in 1943.

Dillwyn — known as "Dilly" — Knox was educated at Summer Fields School, Oxford, and then Eton College. While there he had an affair with John Maynard Keynes. He studied classics at King's College, Cambridge, and in 1909 was elected a fellow.