Fæstningskanalen (literally "The Fortification Canal") is a canal in central Kongens Lyngby, Lyngby-Taarbæk Municipality, Copenhagen, Denmark. Created in the 1880s as part of the new fortification ring around the Danish capital, it runs from Lyngby Lake in the west to Lyngby Hovedgade in the east. From there it originally continued to Ermelunden in Jægersborg Dyrehave, but this last leg of the canal is no longer filled with water.