Prestfoss is a settlement in Sigdal Municipality, in Buskerud, Norway. Prestfoss lies at 120 m above sea level, in the Holtefjell mountains. It has 519 inhabitants (2025). The nearest city is Kongsberg, 42 km to the south. Among the landmarks around are Blaafarveværket (20 km), Rollag Stave Church (20 km) and Flesberg Stave Church (23 km). Among the natural features are Snarumselva (19.7 km) and Haugfoss (20 km).