Limburg (Dutch: Limburg, pronounced [ˈlɪmbʏr(ə)x] ^ⓘ; Limburgish: Limburg [ˈlɪm˦ˌbʏʀ˦əx] or Wes-Limburg [wæsˈlɪm˦ˌbʏʀ˦əx]; French: Limbourg, pronounced [lɛ̃buʁ] ^ⓘ), also known as Belgian Limburg, is a province in Belgium. It is the easternmost of the five Dutch-speaking provinces that together form the Region of Flanders, which is one of the three main political and cultural sub-divisions of modern-day Belgium. As of January 2024, Limburg had a population of 0.9 million.

Limburg is located west of the Meuse (Dutch: Maas), which separates it from the similarly named Dutch province of Limburg. To the south it shares a border with the French-speaking province of Liège, with which it also has historical ties. To the north and west are the old territories of the Duchy of Brabant. Today these are the Flemish provinces of Flemish Brabant and Antwerp to the west, and the Dutch province of North Brabant to the north. Historically Belgian Limburg is roughly equivalent to the Dutch-speaking part of the secular lordship of the medieval Prince-Bishopric of Liège, which was dominated by the County of Loon.

The province of Limburg has an area of 2,427 km² (937 sq mi) which comprises three arrondissements (arrondissementen in Dutch) containing 44 municipalities. Among these municipalities are the current capital Hasselt, and other large towns including Sint-Truiden, Genk, and Tongeren. Tongeren is the only Roman city in the province, and regarded as the oldest city of Belgium.

The municipality of Voeren is geographically detached from Limburg and the rest of Flanders, with the Netherlands to the north and the Walloon province of Liège to the south. This municipality was established by the municipal reform of 1977, and on 1 January 2008, with its six villages, it had a total population of 4,207. Its total area is 50.63 km² (19.55 sq mi).

The name Limburg was not applied to the territory of Belgian Limburg until the 19th century. Instead, the territory broadly coincides with that of the medieval County of Loon, which was one of the main parts of the Prince-bishopric of Liège. In the late-18th century, following the French Revolution and the subsequent French Campaign in the Low Countries, the region became part of the newly created Lower Meuse Department of the French First Republic (later the First French Empire), along with a significant part of what would become Dutch Limburg.

After the defeat of the French empire and the Congress of Vienna in 1815, this department was reconstituted into the Province of Limburg as part of the United Kingdom of the Netherlands. The new name had its own medieval history, being associated with the extinct Duchy of Limburg, which had its capital at nearby Limbourg-sur-Vesdre, now in the French-speaking Belgian province of Liège. The new Dutch monarchy chose this name because it desired to recreate the prestigious old title in a new Duchy of Limburg.

Because of the Belgian revolution in 1830, this province of Limburg was divided in 1839 by the Treaty of London; the western portion being recognised as a province of the newly formed Kingdom of Belgium, while the eastern portion remained part of the Netherlands as the modern Dutch Province of Limburg. Both parts retained the name they had been given by the Dutch monarchy after the defeat of France.

The first wave of people who brought farming and pottery technology from the Middle East to northern Europe was the LBK culture, which originated in central Europe and had its roots in south-eastern Europe. It reached its geographical limit in the fertile southern Haspengouw part of Limburg about 5000 BC, only to die out about 4000 BC. A later wave of farmers, the Michelsburg culture which developed in what is now France, arrived about 3500 BC, but shared a similar fate. Pottery technology had however apparently been taken up by local tribes of the Swifterbant culture, who remained present throughout.