Chainsky District (Russian: Ча́инский райо́н) is an administrative and municipal district (raion), one of the sixteen in Tomsk Oblast, Russia. It is located in the center of the oblast. The area of the district is 7,242 square kilometers (2,796 sq mi). Its administrative center is the rural locality (a selo) of Podgornoye. Population: 12,920 (2010 Census); 13,888 (2002 Census); 17,325 (1989 Census). The population of Podgornoye accounts for 38.6% of the district's total population.