Sergej Ivanovich Ognew (1886–1951) was a Russian zoologist and naturalist, remembered for his work on mammalogy. He graduated from Moscow University in 1910. In 1910 he also published his first book. In 1928, he became a professor at the Pedagogical Institute. He published many books for education about zoology and economy. His most important work which was to be called Mammals of Russia and adjacent territories was never completed.