Chagan (Russian: Чаган; Kazakh: Шаған) is a salt lake in Karasuksky District, Novosibirsk Oblast, Russia,[1] with a small part in Uspen District, Pavlodar Region, Kazakhstan.

Bogatyr town lies by the southwestern shore, in the Kazakh side, and now abandoned Pervomaysky village by the southeastern shore, in the Russian side.

[3] The lake lies in the northern part of the Kulunda Plain.

The Kazakhstan–Russia border runs diagonally off the shore from northwest to southeast across the southwestern side.

[4][2] Lake Chagan has a roughly square shape, with one large bay in the northeast and a smaller one in the northern shore.