Timothy "Tim" Buck (1891 - 1973) was a long-time leader of the Communist Party of Canada (known from the 1940s until the late 1950s as the Labour Progressive Party). Together with Ernst Thalmann of Germany, Maurice Thorez of France, Palmiro Togliatti of Italy, Earl Browder of the United States, and Harry Pollitt of Britain, Buck was one of the top leaders of the Joseph Stalin-era Communist International.