Georgi Petrovich Dementiev (Russian: Гео́ргий Петро́вич Деме́нтьев; 5 July, 1898 – 14 April, 1969) was a Russian and Soviet ornithologist and professor at the University of Moscow. His studies based on museum collections and collaboration with others, notably N. A. Gladkov, resulted in a major six-volume work on the birds of the Soviet Union which was published between 1951 and 1954. He had a special interest in the birds of prey.