The Church of Saint-Genès (fr|Église Saint-Genès de Thiers) is a 12th-century, formerly collegiate, church dedicated to the local martyr Saint Genesius of Thiers (Saint Genès) and situated in the medieval city of Thiers in the department of Puy-de-Dôme in France.The church combines Romanesque and Gothic architecture and possesses the biggest dome of Auvergne with a surface of 102m².[1]