Chetpet lake (Chethupattu Aeri) is a lake spread over 15 acres in Chetput, Chennai, India. It is located to the north of Chetpet railway station. It is the only existing lake at the centre of the city. The lake belongs to the Department of Fisheries of the Tamil Nadu government.
Of the total area of the lake, the waterbody is spread across nearly 9 acres. An anglers club was functioning till the 1940s in the lake, whose members visited the small island in the midst of the waterbody for fishing.
Although not used for drinking purposes, the lake was a source of groundwater recharge for the surrounding areas. As the water quality is not saline, the lake has a few varieties of fishes such as rohu, catla and mrigal. Breeding is monitored to assess the water quality.