German nationality law details the conditions by which an individual is a national of Germany. The primary law governing these requirements is the Nationality Act, which came into force on 1 January 1914. Germany is a member state of the European Union (EU) and all German nationals are EU citizens. They have automatic and permanent permission to live and work in any EU or European Free Trade Association (EFTA) country and may vote in elections to the European Parliament.

Any person born to a married German parent is typically a German national at birth, regardless of the place of birth. Children of unmarried couples in which only the father is German must be legitimised for them to acquire German nationality. Individuals born in Germany to two foreign parents may also receive German nationality at birth if at least one of their parents has lived in the country for eight years and is entitled to live in the country indefinitely (meaning any person with a settlement permit, or citizenship of another EU country or Switzerland). Foreign nationals may naturalise after residing in Germany for at least eight years and demonstrating knowledge in the German language. Although non-EU/Swiss naturalisation candidates are expected to renounce their previous nationalities, the majority are granted permission to retain their old statuses.

Germany is composed of territory historically part of the Holy Roman Empire and German Confederation that was separated into numerous small German states whose residents held citizenship of their locality. Over the course of the 19th century, the various German states moved towards integration into a single entity that culminated with the unification of Germany in 1871. German citizenship was generally held by virtue of being a citizen of a German state, and state citizenship remained a principally important concept in German law until the country's transition to Nazi rule.

Between 1933 and 1945, any person considered "undesirable" by the state (particularly Jews and political dissidents) was stripped of their civil and political rights and targeted for denaturalisation. Any person deprived of their German citizenship during this time based on political, racial, or religious grounds, as well as their direct descendants, are eligible to reclaim German citizenship at any time. Following the end of the Second World War, Germany was split into West Germany and East Germany. While West Germany continued to enforce existing pre-war nationality legislation and claimed all East Germans as its citizens, East Germany adopted a separate nationality law in 1967 which remained in force until German reunification in 1990.