Drolsum is a village in Modum Municipality, in Buskerud, Norway. Drolsum lies at 63 m above sea level, 1.6 km from the Finnemarka mountains. The nearest city is Sandvika, 31 km to the east. Among the landmarks around are Blaafarveværket (13.7 km), Royal Palace (41 km) and Akershus Fortress (42 km). Among the natural features are Hønefossen (22 km) and Snarumselva (8.8 km).