Sergeyevka () is a rural locality (a selo) in Zlatopolinsky Selsoviet, Kulundinsky District, Altai Krai, Russia. The population was 152 as of 2013. There is 1 street.
Sergeyevka lies in the Kulunda Steppe, to the west of lake Dzhira. It is located northeast of Kulunda (the district's administrative centre) by road. Zlatopol is the nearest rural locality.