German is a West Germanic language that is mainly spoken in Central Europe. It is the most widely spoken and (co-) official language in Germany, Austria, Switzerland, South Tyrol (Italy), the German-speaking Community of Belgium, and Liechtenstein. It is also one of the three official languages of Luxembourg. The languages which are most similar to German are the other members of the West Germanic language branch: Afrikaans, Dutch, English, the Frisian languages, Low German/Low Saxon, Luxembourgish, and Yiddish. German is the second most widely spoken Germanic language, after English.

One of the major languages of the world, German is the first language of almost 100 million people worldwide and the most widely spoken native language in the European Union. Together with French, German is the second most commonly spoken foreign language in the EU after English, making it the second biggest language in the EU in terms of overall speakers. German is also the second most widely taught foreign language in the EU after English at primary school level (but third after English and French at lower secondary level), the fourth most widely taught non-English language in the US (after Spanish, French and American Sign Language), and the second most commonly used scientific language as well as the third most widely used language on websites (after English and Russian). The German-speaking countries are ranked fifth in terms of annual publication of new books, with one tenth of all books (including e-books) in the world being published in the German language. In the United Kingdom, German and French are the most-sought after foreign languages for businesses (with 49% and 50% of businesses identifying these two languages as the most useful, respectively).

German is an inflected language with four cases for nouns, pronouns, and adjectives (nominative, accusative, genitive, dative), three genders (masculine, feminine, neuter), and strong and weak verbs. German derives the majority of its vocabulary from the ancient Germanic branch of the Indo-European language family. A portion of German words are derived from Latin and Greek, and fewer are borrowed from French and English. With slightly different standardized variants (German, Austrian, and Swiss Standard German), German is a pluricentric language. Like English, German is also notable for its broad spectrum of dialects, with many unique varieties existing in Europe and also other parts of the world. Due to the limited intelligibility between certain varieties and Standard German, as well as the lack of an undisputed, scientific difference between a "dialect" and a "language", some German varieties or dialect groups (e.g. Low German or Plautdietsch) are alternatively referred to as "languages" and "dialects".