Map - Walloon Brabant (Province du Brabant Wallon)

Walloon Brabant (Brabant wallon ; Waals-Brabant ; Roman Payis) is a province located in Belgium's French-speaking region of Wallonia. It borders on (clockwise from the North) the province of Flemish Brabant (Flemish Region) and the provinces of Liège, Namur and Hainaut. Walloon Brabant's capital- and largest city is Wavre.

The provincial population was recorded at 403,599 as of January 2019, giving a population density of 368 /km2.

Walloon is a Belgian version of a old West Germanic word reconstructed as *walh (“foreigner, stranger, speaker of Celtic or Latin”). Brabant is from Old Dutch *brākbant (attested in Medieval Latin as pāgus brācbatensis, Bracbantum, Bracbantia), from Frankish, a compound of Proto-Germanic *brēk-, *brekaną (“fallow, originally 'to break'”) + *bant-, *bantō, *banti (“district, region”)

Like the terms "Belgium" and "Flanders", the terms "Walloon" and "Brabant" are much older than the modern political entities which they represent today, but were already being used in the region when political boundaries were different. For example, Louis de Haynin wrote as follows in 1628:

* The Belgian [region (contrée or province)] is a large country (pays) between France, Germany and the North Sea. This country is typically divided into two regions [régions] which are about equal, which is to say, Belgian Wallonia and Belgian, or according to some, Flemish Germany [belge wallonne et belge allemagne ou flamande, selons aucun]."

De Haynin noted that the distinction people made in his time between Walloon and German or Flemish Belgium was apparently based upon language, with the Walloons speaking French, and the others speaking what he described as a type of Low German (un bas alleman) which people, especially foreigners, referred to as Flemish. Among the provinces within these two large Belgian regions he contrasted "French or Walloon Flanders", now largely within France, with the rest of "Flanders", and "Lothier or Walloon Brabant (brabant wallon)" with the larger "German or Flemish" part of Brabant, which at that time stretched into what is now the Netherlands. Note that for de Haynin and his contemporaries "Belgium" was much larger than modern Belgium, corresponding to the old Burgundian Netherlands and its associated church-ruled principalities. "Belgium" therefore included all of the Netherlands and Luxembourg, and a part of France. In contrast, the term "Flanders" could be used for a smaller region than today, equivalent to the region once dominated by the County of Flanders, near the north sea. As already noted, de Haynin himself used the adjective "Flemish" to refer to the Dutch language, including dialects outside the old Flemish region, but he noted that the term "Flemish" was now being used to cover a bigger area than it originally applied to, because of the prestige of the old medieval county, which was also well-known to foreigners.