The Isenachweiher in the Palatinate Forest (Rhineland-Palatinate) is a reservoir on the River Isenach, a left tributary of the Rhine.

The Isenachweiher lies in the northeastern Palatinate Forest, 200 metres north of the B 37 federal highway, which runs from the county town of Bad Dürkheim to Frankenstein.

It is part of the forest estated of Bad Dürkheim, whose built up area is about 10 kilometres away.

What is perceived by visitors as the actual lake surface, lies above the dam to the north and is between about 50 and a good 100 metres wide.

An unmetalled car park is located on the dam immediately in front of the house, and there is another on the B 37 at the junction with the access road.