Ivan Yermachenka (Belarusian: Іван Ермачэнка, May 13, 1894 - February 25, 1970) was a Belarusian politician, diplomat and writer.
Ivan Yermachenka was born into a peasant family near Barysau. In 1914 he graduated from a Russian under-officer school. He fought during World War I; by the end of it he reached the rank of polkovnik (colonel). During the Russian Civil War of 1917-1922 Yermachenka fought for the anticommunist White army and served as adjutant to General Pyotr Vrangel. In 1920 he emigrated to Turkey, where he joined the Belarusian national movement.
In 1921 Yermachenka was appointed ambassador of the Belarusian Democratic Republic in Constantinople and general consul for the Balkans. He established Belarusian consulate missions in Bulgaria and in Yugoslavia.
In 1922 he was appointed deputy foreign minister of the democratic Belarusian government in exile in Kaunas. He then moved to Prague where in 1929 he graduated from the Medical Faculty of Charles University.
From 1938 Ivan Yermachenka worked on cooperation between the Belarusian exiled government and Nazi Germany. On 20 April 1939 Yermachenka sent together with Vasil Zacharka, the president of the Belarusian Democratic Republic in exile, a seventeen-page memorandum to Adolf Hitler personally asking him to take into account the interests of Belarus in any future developments. In October 1941 Yermachenka travelled to German-occupied Minsk to set up Belarusian Self-Help, the only legal Belarusian organization at that time. He later became advisor to Wilhelm Kube, the German Generalkommissar of Belarus.