Otto Vasilievich Bremer (died 11 November 1873) was a Russian naturalist and entomologist.
He wrote: Beiträge zur Schmetterlings-fauna des Nödrlichen China's (1853) with Vasilii Fomich Grey (William Grey). "Neue Lepidopteren aus Ost-Sibirien und dem Amur Lande, gesammelt von Radde und Maack, beschrieben von Otto Bremer" (1861) , 3(7): 461-496 "Lepidopteren Ost-Sibiriens, insbesondere der Amur-Landes, gesammelt von den Herren G.Radde, R.Maack und P.Wulfius" (1864) Mémoires de l'Académie impériale des sciences de St.-Pétersbourg, 7 ser., 8(1): 103 pages
He described many insects, including the large skipper butterfly. Bremer's collection is in the Zoological Museum of the Russian Academy of Science in Saint Petersburg where he lived.
References
Anonym 1874: [Bremer, O.] Horae Societatis Entomologicae Rossicae 10(1873).