Novosergiyevsky District () is an administrative and municipal district (raion), one of the thirty-five in Orenburg Oblast, Russia. It is located in the center of the oblast. The area of the district is . Its administrative center is the rural locality (a settlement) of Novosergiyevka. Its population, 36,322 as of the (2010 Census), accounts for 37.8% of the district's total population.
Population: 36,322 (2010 Census);
As of the 2010 Census, the ethnic composition of the population was as follows: