The Kruostas is a river of Kėdainiai district municipality, Kaunas County, central Lithuania.

Originating next to Pakruostė, it flows to the southeast for 8 kilometres (5.0 mi) till discharging into the Nevėžis river (from the right side) near Kalnaberžė village.

Kalnaberžė hillfort stands at the confluence of the Kruostas and Nevėžis.

The river passes through Pakruostėlė, Berželė and Kalnaberžė villages.

This article related to a river in Lithuania is a stub.