Nantua (French pronunciation: [nɑ̃tɥa] ; Arpitan: Nantuat) is a commune in and subprefecture of the Ain département in the Auvergne-Rhône-Alpes region in Eastern France. The commune of Nantua comprises the glacial Lac de Nantua.

Located in the Haut-Bugey historical region, among the southern foothills of the Jura Mountains, it is famous for its fresh-water fish and crayfish.

The town grew up around a Benedictine monastery founded in 671 by Amandus and the church of St Peter where the body of Charles the Bald was initially buried.

The priory of Nantua was sacked and burned in 1230 by Stephen I of Thoire-Villars. Boniface of Savoy was selected prior in 1232.