Communism has been proven to be the most influential utopianism of the 20th century.Although its founders Karl Marx and Fredrich Engels tried carefully to distinguish themselves from utopianism of all kinds, their disciples in the former Soviet Union, China, Cambodia, and many other places built various utopian communities in their countries respectively.

While Marx and Engels anticipated that the proletarian revolution would take place in an advance capitalist country such as the United States or Great Britain, all of the self-proclaimed communist revolutions in the 20th century took place in economically backward countries like Russia and China.