Almsee

Infobox_lake
lake_name = Almsee
image_lake = Almsee1.jpg
caption_lake = View to the shore in the south of the Almsee.
image_bathymetry =
caption_bathymetry =
location = Upper Austria
coords = coord|47|45|N|13|57|E|region:AT_type:waterbody|display=inline,title
type =
inflow =
outflow = Alm
catchment =
basin_countries = Austria
length = 2.3 km
width = 700 m
area = 0.85 km²
depth =
max-depth = 9 m
volume =
residence_time =
shore =
elevation = 589 m
islands =
cities =

Almsee is a lake in Upper Austria in the Almtal valley, south of the town of Grünau im Almtal. The lake lies in the northern portion of the Totes Gebirge mountains and is about 2.3 km by 700 m wide.

The lake drains through Alm. Since 1965, the area around the Almsee is under nature conservation. Konrad Lorenz made important observations of the Greylag Goose on the lake.