German is the sole official language in Germany, Austria and Liechtenstein. It is a co-official language (along with French and other languages) in Belgium, Luxembourg and Switzerland.

However, German is more widely spoken than this brief list might suggest. German is the third most commonly spoken foreign language in the European Union. It is a co-official language, with Italian, in the autonomous Italian province of South Tyrol (Alto Adige), although not a co-official language of Italy itself. A similar situation applies in some Polish communes and in Brazilian municipalities.

More Info: en.wikipedia.org