Olga Fedtschenko (née Armfeldt) was a Russian botanist, geologist and explorer. She made numerous expeditions in the Caucasus, Crimea, southern Urals, Kyrgyzstan, West Tien Shan and Pamir ranges.

Fedtschenko's early explorations were made with her husband, botanist Aleksei Fedtschenko, in 1868-1871. Following Aleksei's death in a climbing accident, Olga organised his scientific collections and published his findings. She continued her botanical fieldwork independently in the 1890s and 1900s, and established a private botanical garden at the family estate near Moscow in 1895. The garden, containing many of the plants she had gathered during her travels, was destroyed by Bolsheviks in 1921.

Olga and Aleksei had a son, Boris, who also became a botanist. Olga brought him up alone, and together they undertook an expedition to the Pamirs in 1901. They jointly published Flora of the Pamirs (1901) and Conspectus Florae Turkestanicae (1913).

Olga Fedtschenko became the second female corresponding member of the Russian Academy of Sciences. Eremurus olgae Regel and more than 40 other plant species are named in her honour.

Sources:
B.A. Starostin and O.A. Valkova, 2006, Olga Aleksandrovna FedchenkoI.T. Vasilczenko, 1972, Russkii Botanicheskii Zhurnal, 57(3): 413-416.