Lake Coghinas (Italian: Lago di Coghinas, Sardinian: Lagu Coghinas) is an artificial lake, in northern Sardinia, Italy, located in the province of Sassari. With a surface of 17.8 km2 and a capacity of 254 million cubic metres of water, it is the second largest lake in the region (second only to Lake Omodeo) and one of the major reservoirs in Italy.

Lake Coghinas
Lago di Coghinas
Lagu Coghinas
Lake Coghinas Lago di Coghinas Lagu Coghinas is located in Sardinia
Lake Coghinas Lago di Coghinas Lagu Coghinas
Lake Coghinas
Lago di Coghinas
Lagu Coghinas
LocationNorthern Sardinia
Coordinates40°44′27″N 9°02′32″E / 40.740754°N 9.042091°E / 40.740754; 9.042091
Typeartificial lake
Primary inflowsCoghinas River, Rio Mannu
Primary outflowsCoghinas River
Basin countriesItaly
Surface area17.8 km2 (6.9 sq mi)
Max. depth50 m (160 ft)
Water volume254×10^6 m3 (206,000 acre⋅ft)

The dam, constructed under Fascism in 1924, is 185 metres long and 58 metres wide. It has the function of water supply, but also it has a hydroelectric power plant.

The lake is the home of a rich ecosystem, and it is become a tourist attraction, around its shores are present a youth hostel, restaurants, a sailing club.