Margaux is an important appellation in the Haut-Médoc district of Bordeaux, southwestern France. Located 25 kilometres (15 miles) north of the city of Bordeaux, the appellation is famous for producing supple, perfumed wines, predominantly from Cabernet Sauvignon.

The Margaux appellation contains 21 cru classé properties from the 1855 Bordeaux Classification (20 of which still exist), more than any other Left Bank appellation. It is also, geographically speaking, the largest in the Médoc, and is divided into five communes or parishes.

In the north, Soussans borders Pauillac. It boasts no cru classé wines, unlike the commune of Margaux to its south. The latter includes ten cru classé chateaux including first growth Château Margaux, and Château Palmer which is "only" a third growth but regarded as one of the great Bordeaux estates. South of Margaux commune Cantenac is home to seven cru classé properties. Giscours and Dauzac are the crus classés based in Labarde, while southernmost Arsac is further inland and the location of fifth growth Château du Tertre.

In Saint-Julien, Saint-Estèphe and Pauillac, the vineyards belonging to each château are often clearly divided and consolidated in a single plot, but in Margaux, this is not the case. Here, even vineyards belonging to the wealthier châteaux are dispersed and mixed in with those of their rivals. The result is that the idea of unique terroirs is diluted, and so winemaking practices and choice of grape varieties play more important roles in the character of wines.

The distinctive flavours and textures of Margaux wines are often attributed to the local soils. In Margaux, the soils have a high gravel content (Pauillac and Saint-Estèphe have slightly more clay), which leads to excellent drainage and a low level of nutrients. Vines grow well in poor, loose, free-draining soil; the poorer the soil, the deeper the vines must go to find water and nourishment. This makes them physically stronger and also allows them to reflect the specific characteristics of the deeper soils. The downside is that Margaux's wines can seem almost too light and delicate in cool vintages.

The grapes permitted for use here are Cabernet Sauvignon, Cabernet Franc, Merlot, Carmenère, Petit Verdot and Malbec. They must come from vineyards planted to densities of 6500 to 10,000 plants per hectare (2631 and 4048 per acre).