Haut-Rhin (French pronunciation: [oʁɛ̃] ) is a department in the Grand Est region, France, bordering both Germany and Switzerland. It is named after the river Rhine. Its name means Upper Rhine. Haut-Rhin is the smaller and less populated of the two departments of the former administrative Alsace region, the other being Bas-Rhin (Lower Rhine), especially after the 1871 cession of the southern territory known since 1922 as the Territoire de Belfort , although it is still rather densely populated compared to the rest of metropolitan France. It had a population of 767,083 in 2021.

On 1 January 2021, the départemental collectivities of Bas-Rhin and Haut-Rhin were merged into the European Collectivity of Alsace.