The famous British leader associated with the D-Day invasion is Winston Churchill. As Prime Minister during World War II, Churchill played a pivotal role in planning and executing Operation Overlord, the code name for the D-Day landings on June 6, 1944. His leadership was crucial in rallying Allied forces against Nazi Germany and in maintaining British morale during the war. Churchill's inspiring speeches and steadfast determination galvanized support for the war effort, making the eventual success of D-Day a turning point in the war. It marked the beginning of the liberation of Western Europe from Nazi occupation.