Otto Fredrik Ström (10 July 1880 – 23 November 1948) was a Swedish politician, editor and a prolific writer.

However, in 1917 Ström broke with Hjalmar Branting and sided with the far left of the party headed by the communists Zeth Höglund and Ture Nerman.

The Swedish Communists took Lenin to the PUB department store where they bought him a brand new suit so he would look good returning home to revolutionary Petrograd.

Ström was head of the Stockholm Comintern liaison with Western Europe from 1919–1920, and he frequently visited the Soviet Union for meetings including the third congress of the Communist International, held in Moscow in 1921.

Ström supported Lenin, Trotsky and the October Revolution, but he disagreed with Stalinism and in 1926 he found his way back to the Swedish Social Democratic Party,[1] although he still considered himself a communist.