Lac du Vieux Emosson

Infobox lake
lake_name = Lac du Vieux Emoson
image_lake = Lac du vieux émosson2.jpg
caption_lake =
image_bathymetry =
caption_bathymetry =
location = Valais
coords = coord|46|3|45|N|6|53|21|E|type:waterbody_region:CH-VS_source:dewiki|display=inline,title
type =
inflow =
outflow =
catchment = 4.6 km²
basin_countries = Switzerland
length = 1.5 km
width =
area = 0.55 km²
depth =
max-depth = 42 m
volume = 13.8 Mio. m³
residence_time =
shore =
elevation = 2205 m
islands =
cities =

Lac du Vieux Emosson is a reservoir in Valais, Switzerland, in the municipality of Finhaut at an elevation of 2205 m. The lake drains into the reservoir Lac d'Emosson, 300 m below.

The arch dam Vieux Emosson was completed in 1955.