Georgi Petrovich Dementiev (23 June (baptized 5 July) 1898 - 14 April 1969) was a Russian 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.