Château Cos d'Estournel is a winery in the Saint-Estèphe appellation of the Bordeaux region of France. It is also the name of the red wine produced by this property. The wine produced here was classified as one of fifteen Deuxièmes Crus in the original Bordeaux Wine Official Classification of 1855.
Château Cos d'Estournel produces the eponymous grand vin, the second wine since the 1994 vintage, Les Pagodes de Cos from the estate's younger vines, as well as Château Marbuzet from fruit of nearby plots. The property is adjacent to Château Lafite-Rothschild in the neighboring commune of Pauillac.