Kalhovdfjorden is a lake in Tinn Municipality in Telemark county, Norway. The lake lies about 20 km to the north of the town of Rjukan and about 15 km east of the Hardangervidda National Park. The lake is part of the Skien watershed. The river Mår is the main outflow of the lake. The lake Møsvatn lies to the southwest and the lake Tinnsjå lies to the southeast. The area of the lake is 20.39 km2 and it is located 1084 m above sea level.