Kadyysky District (Russian: Кады́йский райо́н) is an administrative[1] and municipal[5] district (raion), one of the twenty-four in Kostroma Oblast, Russia.

It is located in the south of the oblast.

The area of the district is 2,190 square kilometers (850 sq mi).

[citation needed] Its administrative center is the urban locality (a settlement) of Kadyy.

[9] The population of Kadyy accounts for 50.5% of the district's total population.