Lake Anosy [anˈuːsi] (French: Lac Anosy) is an artificial lake in the southern part of the capital city of Madagascar, Antananarivo, about two miles south of Haute-Ville.

[1] Ampefiloha is located to the west of the lake, Isoraka to the northwest and Mahamasina to the north.

A swamp was replaced with Lake Anosy during the era of the ruler Radama I.

On the island there is a French-built memorial to those fallen in the first world war, the Monument aux Morts[2][1] made by sculptor Barberis and architect Perrin in 1927.

[1] On the national independence day, June 26, an annual firework festival is arranged on the lake.