Kosh-Agachsky District (Russian: Кош-Ага́чский райо́н, romanized: Kosh-Agachskij raion; Altay: Кӧжӧӧ-Агаш аймак, Koş-Agaş aymak; Kazakh: Қосағаш ауданы, Qosağaş audany) is an administrative[1] and municipal[4] district (raion), one of the ten in the Altai Republic, Russia.

The area of the district is 19,845 square kilometers (7,662 sq mi).

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

[3] Within the framework of administrative divisions, Kosh-Agachsky District is one of the ten in the Altai Republic.

[4] Both administrative[1] and municipal[4] districts are divided into the same twelve rural settlements, comprising sixteen rural localities.