Landes is a department in the Nouvelle-Aquitaine region, Southwestern France, with a long coastline on the Atlantic Ocean to the west. It also borders Gers to the east, Pyrénées-Atlantiques to the south, Lot-et-Garonne to the north-east, and Gironde to the north. Located on the Atlantic coast, it had a population of 413,690 as of 2019. Its prefecture is Mont-de-Marsan.
The department is the second-largest department in France and it covers the Forest of Landes. The southwestern part of the department is part of the wider conurbation of Biarritz and Bayonne across the Pyrénées-Atlantique border.