 Merzweiler borders in the north on the municipality of Hoppstädten, in the east on the municipality of Kappeln, in the southeast on the municipality of Grumbach, in the southwest on the municipality of Herren-Sulzbach and in the west on the municipality of Langweiler.Merzweiler also meets the municipality of Homberg at a single point in the southwest.Merzweiler lies at a crossroads of one road running east-west from Kappeln to Langweiler, and another running north-south from Hoppstädten to Grumbach.