Lake Témiscouata

Infobox lake
lake_name = Lake Témiscouata
image_lake = Pluie au soleil Temiscouata.jpg
caption_lake = Rain in the sun
image_bathymetry =
caption_bathymetry =
location = Témiscouata Regional County Municipality, Quebec
coords = coord|47|40|N|68|50|W|type:waterbody_region:CA-QC|display=inline,title
type =
inflow =
outflow = Madawaska River
catchment =
basin_countries = Canada
length = 45 km
width = 5 km
area =
depth =
max-depth =
volume =
residence_time =
shore =
elevation =
islands =
cities = Cabano

Lake Témiscouata is a lake in the Témiscouata region of southeastern Quebec. It is 45 km long and 5 km wide. The Madawaska River flows from this lake to the Saint John River.

The city of Cabano is located on this lake. Forestry is a major industry in this area.

The Petit Témis Interprovincial Bicycle Path, runs from Rivière-du-Loup, Quebec to Edmundston, New Brunswick, following an abandoned CN Rail line along the lake.

The lake's name means "deep water" in the Míkmaq language.

The lake is theorized to be the inspiration for the nearby parish of Saint-Louis-du-Ha! Ha!. One explanation suggests the archaic French word , here meaning an unexpected obstacle or abruptly ending path, as the lake is an extremely long and particularly formidable obstacle to travel.