Ishim River (; ) is a river running through
Kazakhstan and
Russia. It is long; its average discharge is . It is a left
tributary of the
Irtysh River. The Ishim River is partly navigable in its lower reaches. The upper course of the Ishim passes through
Astana, the capital of Kazakhstan. In Russia, the river travels through a vast marshland for its course, and has countless meanders and
oxbow lakes. The river freezes from late November until March.