Istimis (Russian: Истимис) is a rural locality (a selo) and the administrative center of Istimissky Selsoviet of Klyuchevsky District, Altai Krai, Russia.

Istimis lies in the Kulunda Steppe, near lake Krivaya Puchina to the north and lake Shukyrtuz to the southeast.

[3][4] It is located 17 km northeast of Klyuchi (the district's administrative centre) by road.

Novopoltava is the nearest rural locality.

This Klyuchevsky District location article is a stub.