Alte Oder, River branch in Brandenburg, Germany

The Alte Oder is a branch of the Oder river in Brandenburg, winding through flat lowland meadows and reed beds. The waterway is narrow and lined with dense vegetation on both banks, giving it a quiet, enclosed feel.

The Alte Oder branches were not formed by natural shifts but by cuts through the Oder's meanders. Between 1747 and 1753 the 21-kilometre Oderkanal was dug between Güstebiese and Hohensaaten, leaving the 15 km Güstebieser and 25 km Wriezener Alte Oder as former main channels. Further cuts followed, such as the one at Genschmar in 1787, and near Küstrin-Kietz the name dates from 1736.

The name Alte Oder, "Old Oder", marks channels that were the river's main course until the Oderbruch drainage. The 21 km cut between Güstebiese and Hohensaaten, dug 1747–1753, diverted the main stream, and the old arms now carry the basin's surface water. Towns keep names tied to a river that now runs 7–8 km away: Oderberg lies 7 km west of today's Oder, Bad Freienwalde (Oder) 8 km southwest.

The waterway is accessible by foot along levee paths and field tracks that run beside the banks. The ground can get muddy after rain, so sturdy footwear is a good idea before setting out.

The Güstebieser and Wriezener Alte Oder were the Oder's main channel until the 21-kilometre Oderkanal cut between Güstebiese and Hohensaaten was dug in 1747–1753. The old arms now take all surface water from the Oderbruch, made possible by a water level about 3.5 metres lower than the main stream. Bad Freienwalde still calls itself (Oder) although the river runs 8 km northeast.