Totak is a lake in the municipality of Vinje in Telemark county, Norway. The lake is part of the Skien river watershed ( Skiensvassdraget), discharging via the river Tokke to lake Bandak. At 306 m Totak is the 10th deepest lake in Norway; this tremendous overdeepening marks it as a glacially formed lake with characteristics similar to a fjord. Its volume of 2.36 km makes it the 20th largest by volume as well.
It is part of the Tokke Hydroelectric Power Station.