Bouches-du-Rhône (French pronunciation: [buʃ.dy.ʁon]; Occitan: Bocas de Ròse, lit. "Mouths of the Rhône") is a department in the south of France named after the mouth of the Rhône River. It is the most populous department of the Provence-Alpes-Côte d'Azur region. Its INSEE and postal code is 13.

Bouches-du-Rhône is one of the original 83 departments created during the French Revolution on 4 March 1790. It was created from the western part of the former province of Provence and the principalities of Orange, Martigues, and Lambesc. It lost part of its territory in 1793, including Orange and Apt, when the Vaucluse department was created.

Following its creation, the department was immediately strongly and actively supportive of the French Revolution, containing 90 "Jacobin Clubs" by 1794. It was also noteworthy that more than 50% of the priests in the department accepted the Civil Constitution of the Clergy which in effect subordinated the church to the government. During the ascendancy of the Communist Party in the twentieth century election results indicated that support for left-wing politics remained relatively strong in the department, and especially in the northern suburbs of Marseille.