Sergej Ivanovich Ognew (1886–1951) was a Russian scientist, zoologist and naturalist, remembered for his work on mammalogy. He graduated from Moscow University in 1910, the same year in which he published his first monograph. In 1928, he was ranked a professor at the Moscow State Pedagogical University. He published a variety of textbooks in zoology and economy. His magnum opus, Mammals of Russia and adjacent territories, was never completed.