Levie Jacob "Louis" Fles (1872–1940) was a Dutch businessman, activist and author. He was a member of the organizing committee of the 1928 Summer Olympics. Louis Fles is best known for writing and broadcasting against Zionism and organized religion. Fles was a strong supporter of Jewish assimilation and had a complex relationship with the Dutch Social Democratic Workers' Party. He was a strong criticizer of Nazism, for example in his work from 1933 Hitler, hervormer of misdadiger? (Dutch: Hitler, reformer or criminal?) and committed suicide at the conquest of the Netherlands by Nazi Germany.