Lake Viljandi

Infobox_lake
lake_name = Lake Viljandi
image_lake = Viljandi1.jpg
caption_lake = View from the Viljandi castle ruins.
image_bathymetry =
caption_bathymetry =
location = Viljandi County
coords = coord|58|21|N|25|36|E|type:waterbody_region:EE|display=inline,title
type =
inflow = Valuoja, Köstri stream
outflow = Raudna
catchment =
basin_countries = Estonia
length = 4.33 km
width = 435 m
area = 1.58 km²
depth =
max-depth = 11 m
volume =
shore =
elevation = 42.35 m
islands =
cities = Viljandi

Lake Viljandi (1.55 km²) is a lake in Viljandi County, Estonia. Lake lies in the deep primeval valley of Viljandi, depth 11 m, length 4.6 km, width 450 m. The Uueveski and Valuoja streams and a number of springs flow into the lake. In the south-eastern part of the lake the Raudna river flows out. The main fish in the lake are the bream, the roach, the perch and the pike. The lake and its shores make up the Viljandi landscape protection area.