Dmitry Konstantinovich Zelenin (Russian: Дми́трий Константи́нович Зеле́нин; 1878–1954) was a Russian linguist and ethnographer. He was born in an Udmurt village near Sarapul, where his father was a parish clerk. He attended the Vyatka seminary and the Dorpat University. As of 1915, he read lectures on Slavic dialects at the Petrograd University. He argued that the East Slavs comprise four distinct branches and outlined some subtle differences between East Slavic dialects. In November 2004 the Anthropology Forum of St Petersburg honoured Zelenin with some readings dedicated to him.