Omsky District is an administrative and municipal district (raion), one of the thirty-two in Omsk Oblast, Russia. It is located in the southern central part of the oblast. The area of the district is 3,600 square kilometers (1,400 sq mi). Its administrative center is the rural locality of Rostovka. Population: 94,086 ; 94,251 (2002 census); 90,461 (1989 Soviet census). The population of Rostovka accounts for 5.8% of the district's total population.