Bayonne is a city and commune and one of the two sub-prefectures of the department of Pyrénées-Atlantiques, in the Nouvelle-Aquitaine region of southwestern France. It is located at the confluence of the Nive and Adour rivers in the northern part of the cultural region of the Basque Country. Bayonne is alongside Biarritz the seat of the CA Pays Basque. This is also the southern part of Gascony, where the Aquitaine basin joins the beginning of the Pre-Pyrenees.
Together with nearby Anglet, Biarritz, Saint-Jean-de-Luz, and several smaller communes, Bayonne forms an urban area with 304,890 inhabitants at the 2017 census; 51,228 residents lived in the city of Bayonne proper. It is also a part of Basque Eurocity Bayonne-San Sebastián.
The site on the left bank of the Nive and the Adour was probably occupied before ancient times; a fortified enclosure was attested in the 1st century at the time when the Tarbelli occupied the territory. Archaeological studies have confirmed the presence of a Roman castrum, a stronghold in Novempopulania at the end of the 4th century, before the city was populated by the Vascones.
In 1023 Bayonne was the capital of Labourd.