Sergei Stepanovich Chakhotin (Russian: Сергей Степанович Чахотин; 13 September 1883 – 24 December 1973) was a Russian biologist, sociologist and social democrat. He was the inventor of a technique of "cell optical microsurgery". He applied the ideas of Frederick Winslow Taylor and Ivan Pavlov in developing a theory of political propaganda which he applied in opposing the Bolshevik regime (1917–1919) and the rise of fascism in Europe (in Germany 1930–1933; Denmark 1933–1934; and France 1934–1945). He wrote extensively on organization theory, particularly on the "scientific organization of labour" (Russian: Научная Организация Труда, romanized: Nauchnaya Organizatsiya Truda; also known as NOT).