Sergeyevka () is a rural locality (a village) in Novonadezhdinsky Selsoviet, Blagoveshchensky District, Bashkortostan, Russia. The population was 12 as of 2010. There is 1 street.
Sergeyevka is located 24 km northeast of Blagoveshchensk (the district's administrative centre) by road. Olkhovka is the nearest rural locality.