Lake Siriu

Infobox_lake
lake_name = Lake Siriu
image_lake = Lake Siriu.jpg
caption_lake = Lake Siriu
image_bathymetry =
caption_bathymetry =
location = Romania
coords = coord|45|30|N|26|15|E|type:waterbody_region:RO|display=inline,title
type = artificial lake
inflow = Buzău River
outflow = Buzău River
catchment =
basin_countries = Romania
length = 11.5 km
width =
area = 420 ha
depth =
max-depth =
volume = 155 mio m³ (max)
residence_time =
shore =
elevation =
islands =
cities = Siriu

Lake Siriu is an artificial dam lake in Romania, on the Buzău River valley. Construction of the dam started in 1982, and the 42 MW Nehoiaşu hydroelectric plant was opened in 1994.

The dam is a 122 m high embankment dam with a clay core, the second largest embankment dam in Romania.