The article presents the main biographical information about O. M. Kozhova, algologist, ecologist, and Baikal researcher, who has contributed significantly to the study of the evolution and functional mechanisms of aquatic ecosystems in Eastern Siberia and Mongolia. Her life was connected with the Baikal Limnological Station of the USSR Academy of Sciences, Limnological Institute of the Siberian Branch of the Russian Academy of Sciences, Irkutsk State University and its Institute of Biology. O. M. Kozhova continued the work of her father, Professor M. M. Kozhov. She has perpetuated the Irkutsk and Soviet hydrobiological science schools and empowered them with young professionals. In the 1990s, a time of trials for our science and the country, O. M. Kozhova managed to preserve the Institute of Biology and its staff, and developed promising areas of basic hydrobiological research. O. M. Kozhova left behind a scientific legacy of 706 published and 211 unpublished papers.