Belyayevsky District (Russian: Беля́евский райо́н; Kazakh: Бөрте ауданы, Berte aýdany) 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 3,687 square kilometers (1,424 sq mi). Its administrative center is the rural locality (a selo) of Belyayevka. Population: 17,074 (2010 Census); 20,108 (2002 Census); 19,877 (1989 Census). The population of Belyayevka accounts for 29.2% of the total district's population.