Kolosovsky District (Russian: Колосо́вский райо́н) is an administrative[1] and municipal[4] district (raion), one of the thirty-two in Omsk Oblast, Russia.

It is located in the center of the oblast.

The area of the district is 4,700 square kilometers (1,800 sq mi).

[2] Its administrative center is the rural locality (a selo) of Kolosovka.

[7] The population of Kolosovka accounts for 41.5% of the district's total population.