Ivar Teodor Vennerström (1881[1] - 1945) was a Swedish Social Democratic politician, member of the Riksdag 1915 - 1936. Vennerström joined the left opposition of the Swedish Social Democratic Party in the split of 1917, and initially supported the Bolshevik revolution in Russia. But Vennerström opposed the Twenty-one Conditions of the Communist International and left the Left Party in 1921 as it became the Communist Party of Sweden. Vennerström rejoined the Social Democratic Party in 1924[2] and he was made Minister for Defence 1932 - 1936.[3]