Nils Svante Flyg (9 June 1891 – 9 January 1943) was a Swedish Communist politician who turned pro-Nazi during World War II.

Flyg became an important leader of the Communist Party, wrote books and went on political trips to the Soviet Union.

Flyg and Kilbom who supported Nikolai Bukharin and his Right Opposition, gradually developed an animosity towards Stalinism.

But by the end of the 1930s, the party had changed its view and criticized the whole of the Soviet Union, a stance that gradually developed to a foreign policy embracing Nazi Germany.

[citation needed] He was against capitalism and imperialism and openly supported the basic ideas of Marx and Lenin.