Eduard Otto Emil Karl Adam Freiherr von Stackelberg (6 November 1867 in Sillamäe, Estonia – 7 April 1943 in Munich, Germany) was an Estonian chemist, landowner and politician who belonged to the Stackelberg family. As a chemist, he proposed a model for the periodic table in 1911. He was among the Baltic German landowners deported to Siberia, first by the Tsarist authorities and later by the Bolsheviks. Following World War I he lived in Germany. In 1927 he published a memoir.