Valserhône is a commune in the Ain department in the Auvergne-Rhône-Alpes region in Eastern France. It is the result of the merger, on 1 January 2019, of the communes of Bellegarde-sur-Valserine, Châtillon-en-Michaille and Lancrans. In 2018, the three communes had a combined population of 16,431, with Bellegarde-sur-Valserine as the major population centre. This makes Valserhône the third-most populated commune of Ain, after Bourg-en-Bresse and Oyonnax.