Château Cantemerle is a winery in the Haut-Médoc appellation of the Bordeaux wine region of France, in the commune of Macau. The wine produced here was the final estate to be classified as one of eighteen Cinquièmes Crus (Fifth Growths) in the Bordeaux Wine Official Classification of 1855. The estate has a long history in the Haut-Médoc with records detailing its existence since at least the 12th century and wine production since at least the 14th century. In the 19th century, the estate was hard hit by the phylloxera epidemic as well as grapevine attacks of downy mildew, after which production dropped nearly 50%. Towards the end of the 20th century, the estate was sold to French insurance group Les Mutuelles d'Assurance du Bâtiment et des Travaux Public who have contributed significant investment in the estate's vineyards and winemaking facilities.