Theodor Fischer (1878–1957) was a Swiss art dealer and auctioneer in Lucerne who after the First World War built a highly successful firm of auctioneers that dominated the Swiss art market. In 1939 he was the auctioneer at the infamous Grand Hotel auction of "degenerate art" removed from German museums by the Nazis. During the Second World War he played a key part in the trading of art looted by the Germans from occupied countries.