Ust-Ishimsky District (Russian: Усть-Иши́мский райо́н) is an administrative and municipal district (raion), one of the thirty-two in Omsk Oblast, Russia. It is located in the northwest of the oblast. The area of the district is 7,846 square kilometers (3,029 sq mi).} Its administrative center is the rural locality (a selo) of Ust-Ishim, which, as its name indicates, is located at the confluence of the Ishim River with the Irtysh. Population: 13,480 (2010 Census); 16,479 (2002 Census); 21,670 (1989 Census). The population of Ust-Ishim accounts for 35.6% of the district's total population.