River IJssel, sometimes called Gelderse IJssel (Gelderland IJssel) to avoid confusion with its Holland counterpart, is a 120 km long branch of the Rhine in the Dutch provinces of Gelderland and Overijssel. It flows north from the city of Arnhem until it discharges into the IJsselmeer ("Lake IJssel", until 1932 known as the Zuider Zee). It is one of the three major distributary branches into which the Rhine divides itself shortly after crossing the German-Dutch border, the other two being the Nether Rhine and Waal rivers. The name IJssel is thought to derive from the Germanic i sala, meaning "dark water".

The IJssel once was the lower part of the Oude IJssel ("Old IJssel", German Issel ), a small river that rises in Germany and is now a 70 km long tributary of the IJssel, merging with the main IJssel at Doesburg. The connection between the Rhine and the IJssel was probably artificial in origin, constructed by the Roman general Nero Claudius Drusus as a defence against Germanic tribes.

The following canals and tributary streams connect to the IJssel:

• Apeldoorns Kanaal (west) near the town of Dieren
• river Oude IJssel (east) at the city of Doesburg
• the Berkel stream (east) at the city of Zutphen
• the Twentekanaal (east) between Zutphen and the village of Eefde (municipality of Gorssel)
• the Schipbeek stream (east) near the city of Deventer
• the Grift stream (west) at the town of Hattem; its lower reaches have been channelised to form the mouth of the Griftkanaal
• the Willemsvaart canal (east) at the city of Zwolle
• the Zwolle-IJsselkanaal (east) near Zwolle

At the city of Kampen, river IJssel flows into the IJsselmeer through a small delta, the branches of which are called, west to east, Keteldiep , Kattendiep , Noorddiep , Ganzendiep and Goot . Of these, the Keteldiep and Kattendiep channels are the main navigational arteries; the Noorddiep has been closed off at both sides.

Railroad bridges (with nearest train station on the left and right bank):

• between Arnhem Velperpoort and Duiven
• between Brummen/Klarenbeek and Zutphen
• between Apeldoorn and Deventer
• between Wezep and Zwolle

See also

• Hollandse IJssel