Sisteron Cathedral, now the Church of Notre-Dame-des Pommiers (Cathédrale or Concathédrale Notre-Dame-et-Saint-Thyrse de Sisteron; Église Notre-Dame des Pommiers, or "Our Lady of the Appletrees") is a Roman Catholicchurch located in Sisteron, Alpes-de-Haute-Provence, France. It was formerly a cathedral, and is a national monument.