Salvatnet[3] is a lake in Namsos Municipality in Trøndelag county, Norway.

With its deepest depth of 482 metres (1,581 ft), it is Norway's and Europe's second-deepest lake, after Hornindalsvatnet.

Alternate sources give the depth as either 464 metres (1,522 ft) (old manual method) or 482 metres (1,581 ft) (modern echo sounding method) at the deepest point.

The lower layer of the lake is highly saline and as a result denser than the higher levels of water.

Other meromictic lakes in Norway; with old seawater in the lower depths include Botnvatnet, Kilevann, Rossfjordvatnet, Rørholtfjorden an arm of the lake Tokke, Rørhopvatnet, Tronstadvann, and Øvervatnet.