Saint-Julien is a small but important red wine appellation of the Haut-Médoc district on the Left Bank of Bordeaux in south-western France. Its reputation is based on its status as a reliable source of consistently elegant, age-worthy wines.

Sandwiched between the more famous appellations of Pauillac and Margaux, Saint-Julien is sometimes unfairly overlooked because it does not have a first growth chateau in the 1855 Bordeaux classification. Pauillac has three of the five Médoc first growths and Margaux has one.

Saint-Julien makes up for this by being home to 11 classed growths, which generate three-quarters of the appellation's output. Five of these are highly rated second growths: Châteaux Léoville-Las Cases, Léoville Poyferré, Léoville Barton, Gruaud-Larose and Ducru-Beaucaillou. The first three were once a single estate, which would have been extremely large for its time. The third growths are Langoa-Barton and Lagrange; the fourth growths are Châteaux Beychevelle, Branaire-Ducru, Talbot and Saint-Pierre. All but the latter property are likely to be familiar to most collectors; Château Saint-Pierre is relatively small with 17 hectares (42 acres) of vineyard which supply a wine made at the unclassified Château Gloria.

Almost every acre of the Saint-Julien commune is covered with vines, except for a strip about 500 meters (1600ft) wide on the silted banks of the Gironde estuary to the west. The châteaux which own them can be split into two neat groups: those around the village of Saint-Julien-Beychevelle and those around the village of Beychevelle. These two similarly named villages are only 2 kilometres (1.5 miles) apart, which illustrates the smallness of scale that operates in the Médoc. In fact, the vineyards in the north of Saint-Julien back directly onto the vineyards of Château Latour in Pauillac, yet the wines they produce are different in both status and style.

The appellation laws for Saint-Julien - established in 1936 with many other regulations in Bordeaux - state that its wines must be made from grapes grown in the commune of Saint-Julien Beychevelle, or very specific parts of the communes of Cussac and Saint-Laurent. The document lists the plots (parcelles) eligible for the title.

The grapes permitted for use here are Cabernet-Sauvignon, Cabernet Franc, Merlot, Carmenère, Petit Verdot and Malbec. They must come from vineyards planted to a minimum density of 6500 plants per hectare (2631 per acre), with specified vine-management techniques.

Saint-Julien is bordered to the west by the Saint-Laurent commune, whose wines are eligible only for the wider Haut-Médoc appellation. An example of the effect of this can be found in Saint-Laurent's Chateau Belgrave. It lies just a few hundred meters from Château Lagrange, which can claim the valuable Saint-Julien name, yet Chateau Belgrave cannot.

As is the case with many other prestigious Bordeaux appellations, national and foreign investment is common in Saint-Julien. Châteaux here are owned by a combination of wealthy individuals and international companies.