Lake Langano (Oromo: Hora Langaanoo, Amharic: ላንጋኖ ሐይቅ) is a lake in the Oromia Region of Ethiopia, exactly 200 kilometers by road south of the capital, Addis Ababa, on the border between the East Shewa Zone and Arsi Zones.

[1] It is located to the east of Lake Abijatta in the Main Ethiopian Rift at an elevation of 1,585 meters.

According to figures published by the Central Statistical Agency, Lake Langano is 18 kilometers long and 16 km wide, with a surface area of 230 square kilometers and a maximum depth of 46 meters.

However this is not the case, the reason for the colour is due to the richness of minerals including high sulphur levels which have led many to believe that the lake water has healing properties.

[4] After the earthquake of 1906 there formed a 25–30 m tall geyser on Edo Laki Island on the northern part of the lake.