Vallendar is a town in the district Mayen-Koblenz, in Rhineland-Palatinate, Germany. It is situated on the right bank of the Rhine, approx. 4 km north-east of Koblenz. Vallendar is the seat of the Verbandsgemeinde Vallendar.

Between Bingen and Bonn, Germany, the river Rhine flows as the Middle Rhine through the Rhine Gorge, a formation created by erosion, which happened at about the same rate as an uplift in the region, leaving the river at about its original level, and the surrounding lands raised. This gorge is quite deep, about 130 metres (430 ft) from the top of the rocks down to the average water-line.