Brussels is the capital city of Belgium and the European Union . Brussels ( , pronounced ; , pronounced ) , officially the Brussels Region or Brussels-Capital Region ( , Dutch : ) , is the de facto capital of Belgium and of the European Union ( EU ) . It is also the largest urban area in Belgium , comprising 19 municipalities , including the municipality of the City of Brussels , which is the de jure capital of Belgium , in addition to the seat of the French Community of Belgium and of the Flemish Community .