Association football is the most popular sport in Belgium, which has been played since the end of the 19th century. Around 60% of Belgians are considered football fans. Neighbouring countries with an equal or higher percentage are France, Germany and the Netherlands. The national association was founded in 1895 with the intention of bringing some order and organization to the sport. The first match of the Belgium national team was played on 1 May 1904, a 3–3 draw against France.

Traditionally, the clubs Anderlecht, Club Brugge and Standard Liège are the three most dominant domestic teams, all of them also having played and/or won one or more UEFA competitions final(s).

Both the national football team and the top Belgium division have a reputation for physical play. This came as a result of a lack of technically skilled foreign players allowed to play in Belgium due to legal restrictions. This changed after the Bosman ruling which forced the liberalization of the football player market in Europe. In response, Belgian clubs began to buy unknown players from Eastern Europe, South America and Africa. This had two contradictory consequences. On the one hand, the national team was weakened by the reduced opportunity for native Belgium players to gain a spot on domestic teams. On the other hand, the Jupiler League reinforced its status as an entry league for players who then move on to some of the greatest European clubs.

Indeed, some of the most talented players in Europe have played in Belgian clubs, including Yaya Touré, Jean-Pierre Papin, Daniel Amokachi, Antolín Alcaraz and David Rozehnal were discovered at Club Brugge; Sunday Oliseh and Victor Ikpeba at RFC Liège; Jan Koller, Nii Lamptey and Aruna Dindane at Anderlecht; and Mido at Gent.

Others who began or launched their professional careers in Belgium include William Carvalho, Emmanuel Eboué, Romaric, Gervinho, Didier Zokora, Arthur Boka, Ivica Dragutinović, Mario Stanić, Morten Olsen, Dorinel Munteanu, André Cruz, Seol Ki-hyeon, Kennet Andersson, Klas Ingesson, Aaron Mokoena, Michaël Ciani, Nicolás Pareja, Oguchi Onyewu, Rabiu Afolabi, Cheick Tioté, Peter Odemwingie, Joseph Yobo, Ouwo Moussa Maazou, Milan Jovanović, Ognjen Vukojević, Ivan Perišić, Nikica Jelavić, Demba Ba, Dante, Bryan Ruiz and Rob Rensenbrink.

Because of the physical nature of Belgian football, it has tended to primarily produce talented defensive players. These include Jean-Marie Pfaff, Eric Gerets, Leo Clijsters, Michel Preud'homme, Georges Grün, Philippe Albert, Franky Van Der Elst, Vincent Kompany and Thomas Vermaelen. In comparison, only few attacking Belgian footballers have received international recognition: Enzo Scifo, Jan Ceulemans, Marc Degryse, Luc Nilis and Émile Mpenza.

However, this latter trend is slowly starting to change, with Belgium producing such offensive talents as Romelu Lukaku, Eden Hazard, Mousa Dembélé, Christian Benteke, Kevin Mirallas, Marouane Fellaini, Kevin De Bruyne and Dries Mertens, among others.

With football's rapid growth in popularity in the late 19th century, several football clubs came into existence in Belgium. In 1926, the Royal Belgian Football Association decided to introduce matricule numbers to tell the clubs apart and assigned a matricule to each existing club by order of registration. In this manner, Antwerp was awarded matricule number 1 as the first to register. As such, the oldest clubs in Belgium typically have the lowest matricule numbers, although there are clubs which registered many years after their origination and as a result have a much higher matricule than would be expected. Many clubs, especially those with very low numbers, consider their matricule number part of their heritage and past and prominently feature it in their logo or even name. In case a club dissolves, the matricule number of this club is removed permanently and lost forever as numbers are never reused.