Château Margaux, archaically La Mothe de Margaux was one of four wines to achieve Premier cru (first growth) status in the Bordeaux Classification of 1855. The estate is located in the commune of Margaux on the left bank of the Garonne estuary in the Médoc region.

The estate also produces a second wine named Pavillon Rouge du Château Margaux, a third wine named Margaux de Château Margaux, as well as a dry white wine named Pavillon Blanc du Château Margaux which does not conform to the Margaux appellation directives.

The estate has been occupied since at least the 12th century, with the site occupied by a fortified castle known as Lamothe or La Mothe (from motte, a small rise in the land), and wine under names such as "Margou" and "Margous" was known in the 15th century, but it was with the arrival of the Lestonnac family in the 16th century that wine production became of particular importance.

By the beginning of the 18th century, the estate comprised 265 hectares (650 acres) with a third devoted to viticulture, which is nearly identical to the modern layout.

Following the French Revolution, the owner Elie du Barry was executed by guillotine and the estate expropriated, eventually becoming the property of the citizen Miqueau who neglected its care and maintenance. Briefly rescued by Laure de Fumel, she was soon forced to sell, and in 1802 the estate was purchased by the Marquis de la Colonilla, Bertrand Douat.

The estate's old château was torn down and completely rebuilt when Douat commissioned one of Bordeaux' foremost architects, Louis Combes, to create the buildings in the First Empire style, the mansion for the Marquis to move into by 1812.

Large portions of shares in the estate were bought by the Bordeaux wine merchant Fernand Ginestet (then owner of the adjacent Château Lascombes) in 1925, and the family share was gradually increased to allow his son Pierre Ginestet to take complete ownership in 1949. In 1965, Pierre Ginestet controversially declared a new estate policy that the vintage year would only be affixed to great vintages, while selling the wine of lesser years as non-vintage wine, like the customary practice of Champagne.

Following the Bordeaux economic crisis of 1973, the Ginestet family were forced to sell Château Margaux.

A successful acquisition took place in 1976 by French grocery and finance group Félix Potin, headed by Greek André Mentzelopoulos. By the time of Mentzelopoulos' death in 1980, Château Margaux was considered substantially restored to its former reputation, with the 1978 and 1979 vintages declared "exceptional".

At the beginning of the 1990s, an exchange of shares was negotiated with the Agnelli family but the management remained in the hands of Mentzelopoulos' daughter Corinne Mentzelopoulos. In 2003, Corinne Mentzelopoulos bought back the majority stake and became the sole shareholder of Château Margaux.

The domaine of Château Margaux extends 262 hectares (650 acres), of which 87 hectares (210 acres) are entitled to the Margaux AOC declaration. 80 hectares (200 acres) are planted with 75% Cabernet Sauvignon, 20% Merlot, with 2% Cabernet Franc and Petit verdot. 12 hectares (30 acres) are cultivated with Sauvignon Blanc to make the dry white Pavillon Blanc.

The average annual production of the Grand vin, Château Margaux, is 150,000 bottles, while the second wine Pavillon Rouge du Château Margaux has an average production of 200,000 bottles. The dry white Pavillon Blanc du Château Margaux has a production of around 35,000 bottles, and must be sold under the generic Bordeaux AOC as the cultivation of Sauvignon Blanc does not fall under the directives of the Margaux AOC. The remainder of the production, what is determined to be "lesser grapes", is sold off in bulk.