Thomas Duff may refer to: Thomas Duff (architect) (1792–1848), Irish architect Thomas Duff (businessman) (born 1956), American businessman Thomas Duff (politician) (1870–1949), Australian politician Thomas J. Duff, American architect Thomas Neil Duff (1896–1978), politician in Ontario, Canada Tom Duff (born 1952), Canadian computer programmer Tommy Duff (1905–1951), English footballer