Eğirdir (Turkish: Eğirdir Gölü, formerly Eğridir) is a lake in the Lakes Region of Turkey. The town of Eğirdir lies near its southern end, 107 kilometers north of Antalya. With an area of 482 square kilometres it is the fourth largest lake in Turkey, and the second largest freshwater lake.
Lake Eğirdir is fed by about 40 different springs, some of which are intermittent, and also by rainfall within its 3,309-km2 drainage basin. The main streams which feed Lake Eğirdir are the Pupa, the Hoyran, the Yalvaç, and the Çay. Besides evaporation, water exits Lake Eğirdir either by flowing out through the Kovada Canal into Lake Kovada, by draining out into one of the about 20 natural ponors that exist at the bottom of the lake, or by being pumped out through one of the 11 irrigation pumps built around the lake. The average retention time for water in the lake is 2.5 to 3 years.
The lake has an average depth of 7 m and a maximum depth of 13 m. Significant fluctuations in Lake Eğirdirs water level are not uncommon. It has a total volume of 4,000 cubic hectometres, of which 1,000 cubic hectometres is drawn off for irrigation, drinking water, or other human uses. Approximately 45,000 hectares are irrigated by waters drawn from the lake.
A strait called the Hoyran Boğazı divides Lake Eğirdir into two parts: the larger Eğirdir Gölü proper and the smaller Hoyran Gölü.
