Otto John Maenchen-Helfen (in German: Otto Mänchen-Helfen) (July 26, 1894 in Vienna, Austria – January 29, 1969 in Berkeley, California) was an Austrian academic, sinologist, historian, author, and traveler.
From 1927 to 1930 he worked at the Marx-Engels Institute in Moscow, and from 1930 to 1933 in Berlin. When the Nazis came to power in Germany, he returned to Austria, and after the Anschluss in 1938 he emigrated to the United States, eventually becoming a professor at the University of California, Berkeley. He was the author of several oft-cited books, including a history of the Huns.
He was the first non Russian to travel and report on Tannu Tuva. He obtained permission to travel there and study its inhabitants in 1929 He later published his experiences in a book, Reise ins asiatische Tuwa .