| Lake Lesina | |
| Native Name: | Italian: Lago di Lesina |
| Location: | Province of Foggia, Apulia |
| Coords: | 41.8878°N 15.4403°W |
| Lake Type: | lagoon |
| Pushpin Map: | Italy Apulia |
| Outflow: | Foce Acquarotta, Foce Schiappàro |
| Catchment: | 447km2 |
| Basin Countries: | Italy |
| Length: | 22km (14miles) |
| Width: | 3.5km (02.2miles) |
| Area: | 51.4km2 |
| Depth: | 0.7m (02.3feet) |
| Max-Depth: | 1.7m (05.6feet) |
| Residence Time: | 100 days (summer 306 days, winter 31 days) |
| Elevation: | 0m (00feet) |
Lake Lesina or Lacus Pantanus (Italian: '''Lago di Lesina''' or Italian: '''Laguna di Lesina'''), situated in the north of Apulia between Tavoliere delle Puglie and the promontory of Gargano, is the ninth largest lake in Italy and the second largest in the southern part of the country. It is brackish, about 22 km long, an average of 2.4 km wide, and covers an area of 51.4 square kilometres.Two canals, Acquarotta and Schiapparo, link it the lake to the Adriatic Sea, from which it is separated by a long dune known as Bosco Isola, between one and two kilometres in width and sixteen in length. Numerous streams provide the lake with a modest supply of fresh water.
The lake is very shallow with an average depth of about 70 cm and a maximum depth of less than 2 metres. Its large population of eels provides a traditional source of income for the people of Lesina.