Lake Peigneur (locally pronounced [pæ̃j̃æ̹ɾ]) is a brackish lake in the U.S. state of Louisiana, 1.2 miles (1.9 kilometers) north of Delcambre and 9.1 mi (14.6 km) west of New Iberia, near the northernmost tip of Vermilion Bay. With a maximum depth of 200 feet (60 meters), it is the deepest lake in Louisiana. Its name comes from the French word "peigneur", meaning "one who combs."

It was a 10-foot-deep (3 m) freshwater body, popular with sportsmen, until an unusual man-made disaster on November 20, 1980 changed its structure and the surrounding land.