Beer in Belgium includes abbey beers, lambics, pilsners, Flemish red ales, sour brown ales, strong ales, Wheat beers and others. As of 2024, there were 411 breweries in Belgium, ranging from international companies, such as AB InBev to traditional breweries, like Trappist monasteries, to microbreweries. Correspondingly, the number of Belgian breweries continues to grow, with over 1,600 unique Belgian beers available. On average, Belgians drink 68 litres of beer each year, down from around 200 each year in 1900. In 2024, this amounts to a total consumption of approximately 6.4 million hectoliters, representing around 30% of Belgium’s total beer production.

In 2016, UNESCO inscribed Belgian beer culture on their list of the intangible cultural heritage of humanity.

In Belgium, beer was already produced in the Roman era, as evidenced by the excavation of a brewery and malthouse from the 3rd and 4th centuries AD at Ronchinne. During the Early and High Middle Ages, beer was produced with gruit, a mix of herbs and spices that was first mentioned in 974 when the bishop of Liège was granted the right to sell it at Fosses-la-Ville. From the 14th century onwards, gruit was replaced by hops, after the example of imported beers from northern Germany and Holland. After that, several Belgian towns developed their own types of beer for export to other regions, most notably the white beer of Leuven and Hoegaarden, the caves of Lier and the uitzet of Ghent. In recent years, the use of gruit has experienced a revival, particularly among homebrewers and eventually by commercial breweries. For instance, Gageleer brews a beer using sweet gale (Myrica gale) based on a medieval recipe.

Monasteries played only a small role in beer production and mostly brewed for their own consumption and that of their guests. Monastic brewing would only receive some renown from the late 19th century onwards, when the Trappists of Chimay produced a brown beer that was commercially available.

In 1885, a change in legislation made brewing of German-style bottom-fermenting beers viable in Belgium, and it was only from then that large industrial-scale brewing in Belgium took off. During the 20th century the number of breweries in Belgium declined from 3223 breweries in 1900 to only 106 breweries in 1993. Yet, a number of traditional beer styles, such as white beer, lambic and Flemish old brown were preserved, while new local, top-fermented styles developed, such as spéciale belge, abbey beer and Belgian strong ale. In 1988, the country's two biggest breweries, Artois and Piedboeuf, formally merged to become Interbrew, then the world's 18th biggest brewer, which was to merge with AmBev in 2004 to become today's AB InBev, the biggest beer producing company in the world.

In Belgium, four types of fermentation methods are used for the brewing of beer, which is unique in the world. However, for good understanding of labels of Belgian beer and reference works about Belgian beer often use different terms for the fermentation methods based on archaic or traditional jargon:

Belgian beers have a range of colours, brewing methods, and alcohol levels.

Beers brewed in Trappist monasteries are termed Trappist beers. For a beer to qualify for Trappist certification, the brewery must be in a monastery, the monks must play a role in its production and the policies and the profits from the sale must be used to support the monastery or social programs outside. Only ten monasteries currently meet these qualifications, five of which are in Belgium, two in the Netherlands, one in Austria, one in Italy and one in the United Kingdom. Trappist beer is a controlled term of origin: it tells where the beers come from, it is not the name of a beer style. Beyond their being mostly warm fermented, Trappist beers have very little in common stylistically.