Illsee

Infobox lake
lake_name = Illsee
image_lake =
caption_lake =
image_bathymetry =
caption_bathymetry =
location = Sierre, Valais
coords = coord|46|15|27|N|7|37|57|E|type:waterbody_region:CH-VS_source:dewiki|display=inline,title
type = natural lake, reservoir
inflow =
outflow = Illbach
catchment = 5.9 km²
basin_countries = Switzerland
length = 0.2 km
width =
area = 0.21 km²
depth =
max-depth = 64 m
volume = 6.6 mio m³
residence_time =
shore =
elevation = 2360 m
islands =
cities =

Illsee is a natural lake used as a reservoir above Sierre, in the Valais, Switzerland. Its surface area is 0.21 km².