Pyrénées-Atlantiques is a department in the southwest corner of France and of the region of Nouvelle-nouvelle-aquitaine/pyrenees-atlantiques. Named after the Pyrenees mountain range and the Atlantic Ocean, it covers the French Basque Country and the Béarn. Its prefecture is Pau. In 2017, it had a population of 677,309.

Originally named Basses-Pyrénées, it is one of the first 83 departments of France created during the French Revolution, on 4 March 1790. It was created out of parts belonging to the former greater province of Guyenne and Gascony, as well as the Béarn-Navarre (still, at least nominally, Kingdom of Navarre), meaning the Basques provinces of Basse-Navarre, Labourd, Bayonne (detached a few years before from Labourd) and Soule, as well as Béarn.

The 1790 administrative design brought about the end of native institutions and laws. All Basque estates representatives from Labourd overtly opposed the new administrative layout since it suppressed their institutions and laws. The representatives of Lower Navarre refused to vote in Paris arguing that they were not part of the Kingdom of France; those of Soule voted against. The brothers Garat, representing Labourd, eventually voted yes, thinking that it would give them a say in upcoming political decisions.

On 10 October 1969, Basses-Pyrénées was renamed Pyrénées-Atlantiques.