 The municipality lies in the Westrich – an historic region that encompasses areas in both Germany and France – at the boundary with the Saarland.Reichweiler, once in the southeast of the Birkenfeld district but today in the westernmost Kusel district, stretches out at the southern foot of the Karrenberg, itself part of the "Preußische Berge" (Prussian Mountains), a mighty mountain chain that looms up northwest of the Pfeffelbach valley, reaching an average elevation of almost 600 m above sea level.The district's highest peak is the Herzerberg (585 m), which lies within Reichweiler's limits.