The Nedonas (Greek: Νέδωνας, katharevousa: Νέδων Nedon) is a river Messenia, Peloponnese, Greece.

[1] The river rises on the western slope of the Taygetus mountains, at around 1,100 m elevation, near the village Artemisia.

It flows in southwestern direction, through a steep and narrow gorge.

It flows through the city centre of Kalamata, where it empties into the Messenian Gulf.

The Greek National Road 82 (Pylos - Kalamata - Sparta) runs along the river for a part of its length.