Duff Cooper, English politician and diplomat, Chancellor of the Duchy of Lancaster (b. 1890)
Alfred Duff Cooper, 1st Viscount Norwich, (22 February 1890 – 1 January 1954), known as Duff Cooper, was a British Conservative Party politician and diplomat who was also a military and political historian.

First elected to Parliament in 1924, he lost his seat in 1929 but returned to Parliament in the 1931 Westminster St George's by-election, which was seen as a referendum on Stanley Baldwin's leadership of the Conservative Party. He later served in the Cabinet as Secretary of State for War and First Lord of the Admiralty. In the intense political debates of the late 1930s over appeasement, he first put his trust in the League of Nations, and later realised that war with Germany was inevitable. He denounced the Munich agreement of 1938 as meaningless, cowardly, and unworkable, as he resigned from the cabinet.

When Winston Churchill became prime minister in May 1940, he named Cooper as Minister of Information. From 1941, he served in numerous diplomatic roles. He also served an important role as representative to Charles de Gaulle's Free France (1943–44) and ambassador to France from 1944 to 1948.