The Beneden Merwede is a stretch of river in the Netherlands, mainly fed by the river Rhine. It starts as the continuation of the Boven Merwede after the branching-off of the Nieuwe Merwede ship canal. It flows from Hardinxveld-Giessendam to Dordrecht, where it splits into the Noord and Oude Maas rivers. Its length is 14.8 km.