Warta (Latin: Varta, German: Warthe) is a river in western-central Poland, a tributary of the Oder river. With a length of approximately 808 kilometers it is the country's third longest river. Warta has a basin area of 54,529. It is connected to the Vistula by the river Noteć and the Bydgoszcz Canal (Kanał Bydgoski).
