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

It flows for 8.2 kilometres (5.1 mi).

It originates at the edge of the Krakės-Dotnuva forest nearby Palainiškiai, then flows to the southeast till it meets the Smilga (from the left side) nearby Lipliūnai.

The name Graisupis possibly comes from Lithuanian verb greisti ('to become quicker').

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