Bas-Rhin

Bas-Rhin (French pronunciation:) is a department in Alsace which is a part of the Grand Estregion of France. The name means 'Lower Rhine', referring to its lower altitude among the two French Rhine departments: it is downstream of the Haut-Rhin (Upper Rhine) department. Both belong to the European Upper Rhine region. It is, with the Haut-Rhin (Upper Rhine), one of the two departments of the traditional Alsace region which until 1871, also included the area now known as the Territoire de Belfort. The more populous and densely populated of the pair, it had 1,163,810 inhabitants in 2023. The prefecture is based in Strasbourg. The INSEE and Post Code is 67.

On 1 January 2021, the departemental councils of Bas-Rhin and Haut-Rhin merged into the European Collectivity of Alsace.

The inhabitants of the department are known as Bas-Rhinois or Bas-Rhinoises.