The Brussels Metro is a rapid transit system serving a large part of the Brussels-Capital Region of Belgium. It consists of four conventional metro lines and three premetro lines. The metro-grade lines are M1, M2, M5, and M6 with some shared sections, covering a total of 39.9 kilometres (24.8 mi), with 59 metro-only stations. The premetro network consists of three tram lines that partly travel over underground sections that were intended to be eventually converted into metro lines. Underground stations in the premetro network use the same design as metro stations. A few short underground tramway sections exist, so there is a total of 52.0 kilometres (32.3 mi) of underground metro and tram network. There are a total of 69 metro and premetro stations as of 2011.

Brussels, officially the Brussels-Capital Region, is a region of Belgium comprising 19 municipalities, including the City of Brussels, which is the capital of Belgium. The Brussels-Capital Region is located in the central portion of the country and is a part of both the French Community of Belgium and the Flemish Community, but is separate from the Flemish Region and the Walloon Region, located less than 4 kilometres (2.5 mi) to the south. Historically Dutch-speaking, Brussels saw a language shift to French from the late 19th century. Nowadays, the Brussels-Capital Region is officially bilingual in French and Dutch, although French is the majority language and lingua franca. Brussels is also increasingly becoming multilingual. English is spoken widely and many migrants and expatriates speak other languages as well.