Septfontaines (Luxembourgish: Simmer, German: Simmern) is a small town in western Luxembourg.

Located high above the town of Septfontaines, the medieval castle is now privately owned.

The former commune consisted of the villages: The name Septfontaines is a French neologism (the local population is almost entirely Luxembourgish-speaking), derived from the older name Siebenborn (literally, 'seven springs'), which appears as the name of the town in Latin and German documents from the nineteenth century and earlier.

The name Siebenborn was often abbreviated 7born in vital records.

This article related to the geography of Capellen canton is a stub.