Koby is a village in Enköping Municipality, in Uppsala County, Sweden. Koby lies at 35 m above sea level. The nearest city is Enköping, 16.8 km to the southeast. Among the landmarks around are Västerås Cathedral (22 km), Sala Silver Mine (26 km) and Altuna Runestone (10.6 km). Among the natural features are Sätra brunn (27 km).