Kalachinsky District () is an administrative and municipal district (raion), one of the thirty-two in Omsk Oblast, Russia. It is located in the southeast of the oblast. The area of the district is . Its administrative center is the town of Kalachinsk (which is not administratively a part of the district). Population: 18,197 (2010 Census);
Within the framework of administrative divisions, Kalachinsky District is one of the thirty-two in the oblast. The town of Kalachinsk serves as its administrative center, despite being incorporated separately as a town of oblast significanceâÂÂan administrative unit with the status equal to that of the districts.
As a municipal division, the district is incorporated as Kalachinsky Municipal District, with the town of oblast significance of Kalachinsk being incorporated within it as Kalachinsk Urban Settlement.