Is the European Union in Brussels?

Not technically. There is no capital of Europe, as Europe isn't a country, it's a continent. However due to the large numbers of Europe wide institutions, it could be argued that Brussels is the de facto capital of the Europe union as it houses the European commission, the European council and the second seat of the European Parliament.

The EU is comprised of only 27 countries in Europe and excludes European countries such as Norway and Switzerland.